Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Mon, Mar 10, 2008 at 01:03:02PM -0700, Christoph Birk wrote: > On Mon, 10 Mar 2008, Petr Baudis wrote: >>> MoGo displays the depth of the principle variation in the stderr stream. >> >> I have been wondering, does that include _any_ nodes, or only these >> above certain number of playouts? What is the playout threshold? > > The 'principal variation' is usually the one that the program would > play against itself; at each level the one move with the highest > score with might (depending on the program) just be the one with > the most playouts. I guess Petr meant: does Mogo stop what it calls principal variation when all nodes following the move have been visited less than say 100 or 1000 times, or does it follow the ``best'' moves until the very leaves of the UCT tree ? Jonas ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Mon, 10 Mar 2008, Petr Baudis wrote: MoGo displays the depth of the principle variation in the stderr stream. I have been wondering, does that include _any_ nodes, or only these above certain number of playouts? What is the playout threshold? The 'principal variation' is usually the one that the program would play against itself; at each level the one move with the highest score with might (depending on the program) just be the one with the most playouts. Christoph ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Mon, Mar 10, 2008 at 02:33:03AM -0400, Michael Williams wrote: > Jonas Kahn wrote: >> out, kos can go on for long. I don't know what depth is attained in the >> tree (by the way, I would really like to know), but I doubt it is that > > MoGo displays the depth of the principle variation in the stderr stream. I have been wondering, does that include _any_ nodes, or only these above certain number of playouts? What is the playout threshold? -- Petr "Pasky" Baudis Whatever you can do, or dream you can, begin it. Boldness has genius, power, and magic in it.-- J. W. von Goethe ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Mon, Mar 10, 2008 at 02:33:03AM -0400, Michael Williams wrote: > Jonas Kahn wrote: >> out, kos can go on for long. I don't know what depth is attained in the >> tree (by the way, I would really like to know), but I doubt it is that > > MoGo displays the depth of the principle variation in the stderr stream. Thank you for the information. Jonas ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Jonas Kahn wrote: out, kos can go on for long. I don't know what depth is attained in the tree (by the way, I would really like to know), but I doubt it is that MoGo displays the depth of the principle variation in the stderr stream. ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Don Dailey wrote: > I want to make sure I understand the nakade problem, please correct me > if I am wrong: > My understanding of this is that many program do not allow self-atari > moves in the play-outs because in general the overwhelming majority are > stupid moves. Is that what is causing the nakade problem? And if > you start including self-atari you weaken the program in general? I think the self-atari moves are only part of the story. With MogoRelease3, a lot of its life and death errors appear to happen when an approach move is required before the capture can happen, particularly when one player has to go back and make a solid connection on the first line before it can remove one of its opponent's liberties. I guess it isn't considering these moves (which can be thought of as filling a false eye). This can happen even when there is no capturing race involved. Certainly in some positions when Mogo has a game-losing dead group but thinks it's ahead, making such a solid connection can be the trigger for it to realise what's going on and resign. -M- ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Thu, 6 Mar 2008, Weston Markham wrote: You are right, but I think that you may also be misconstruing the nakade problem as a lack of concern about margin, when it is really a fundamental failure to understand (i.e., failure to explore Sorry, you miss-understood. The nakade problem is totally unrelated to the margin problem. They just sometimes happen at the same time and then allow someone to take advantage of them. Christoph ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On 3/6/08, Christoph Birk <[EMAIL PROTECTED]> wrote: > On Thu, 6 Mar 2008, Don Dailey wrote: > > > advantageous to give away stones that not. Despite what many people > > believe, MC programs don't normally believe it's better to win small > > and they are not hell-bent on giving away stones in order to try to make > > the score come out to be exactly 0.5 win. > > > You are correct that it is not explicitly programmed into the MC > programs to win by 0.5 pts, but since most of them don't care about > the margin they in practice often do. You are right, but I think that you may also be misconstruing the nakade problem as a lack of concern about margin, when it is really a fundamental failure to understand (i.e., failure to explore sufficiently) the nakade shapes. The tendancy for your final scores on lost games to be 0.5 really reflects a motivation on your own part to lose by the smallest margin that you can. After a point when the game is resolved, this doesn't conflict with the program's goal, so it lets you do just that. As an interesting thought, I think that it might actually be informative for people to try out programs that _do_ try to win by exactly 0.5! Not as a fundamental goal, but rather as a slight preference for the endgame. If authors can do this in a manner that does not degrade the playing ability much, then human players might be able to see even more clearly what life & death errors a program makes, and at what point it is able to discover the correct solution. Clearly the programs would be weaker like this, but I think it could expose some systematic problems very quickly, so that they could be focused on. Weston ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Thu, 6 Mar 2008, Don Dailey wrote: advantageous to give away stones that not. Despite what many people believe, MC programs don't normally believe it's better to win small and they are not hell-bent on giving away stones in order to try to make the score come out to be exactly 0.5 win. You are correct that it is not explicitly programmed into the MC programs to win by 0.5 pts, but since most of them don't care about the margin they in practice often do. As you might remember I (3 kyu) played many games on CGOS and many games that I lost, I actually lost by 0.5 pts. It mostly worked like this: I am behind by several points in the early endgame, then the programs allow me to gain a point here, or there. But in the end they still win by 0.5 pts. These programs are NOT "hell-bent on losing", they just dont care if the UCT-tree shows that they win anyway. Christoph ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Don Dailey wrote: > Although it's easy to see that nakade is a problem, I agree with > someone who said it takes a lot of skill to produce this. In fact, I > believe that it cannot be done reliably by any player unless he is > already much stronger than the program, in which case he doesn't > "need" to do it in order to beat the program. It turns out not to be difficult at all. When it has a killable group, Mogo actively cooperates to bring about these situations, because it thinks it has found a way to live. I have killed more groups in bent-4 in a few evenings of playing mogo at 13x13 than I have otherwise in the last ten years. > Most MC programs won't just let you pick off points because that is > normally a strategy that decreases your winning chances. They will > only do that if every move leads to the same win or loss in every > single play-out, or if the small win turns out to be easier to manage. If you watch mogo playing on KGS, you will see that when it ahead it does consistently let its opponent 'pick off points' until the game becomes very close. -M- ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Thu, 6 Mar 2008, Don Dailey wrote: And can I assume the tree portion is also inhibited from seeing this due to a combination of factors such as heuristics to delay exploring "ugly" moves as well as the weakness of the play-outs in this regard (which would cause the tree to not be inclined to get close enough to the issue to understand it properly?) It might also be reading-depth. Some nakade forms need quite deep reading you want to "discover" them on-the-fly. 10 kyu humans know that the bulky-five is dead; no reading required. Christoph ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
> You have to have a nakade pattern on the > board somewhere, the score has to be close and in your favor > considering the nakade, and the program has to believe that it is more > advantageous to give away stones that not. eh, or it can't see the capture until it's only a few moves away, because its horizon with respect to self-atari is so shallow. deepen the horizon and it'll consider those moves early enough not to screw up its overall win percentage evaluation. > Although it's easy to see that nakade is a problem, I agree with > someone who said it takes a lot of skill to produce this.In fact, I > believe that it cannot be done reliably by any player unless he is > already much stronger than the program, in which case he doesn't "need" > to do it in order to beat the program. I wouldn't go this far -- humans learn from their mistakes, but can stay at the same skill level regardless of how much they learn, either because they forget things that they earlier learned, or because they have very shallow reading, say. for a computer, though, it's quite possible that every single player ranked one or two stones lower than (arbitrary mc program with this weakness -- AMCW) could exploit this weakness in a systematic way, more than 50% of the time. this would eventually reduce AMCW's ranking, of course, but wouldn't raise any of those player's rankings, because their ability to beat one specific player consistently isn't enough to modify their ranking. > (Indeed, it may be a > counterproductive strategy if it distracts you from playing good moves.) these aren't bad moves in any way. they're normal, healthy, strong go-player moves that are recognized instantly by anyone who has a read a copy of "life and death" or similar. > Most MC programs won't just let you pick off points because that is > normally a strategy that decreases your winning chances. They will > only do that if every move leads to the same win or loss in every single > play-out, or if the small win turns out to be easier to manage. or if they aren't reading out the playouts deeply enough that would allow them to correctly consider the impact of those moves early enough to avoid them! > I would love to see a 5kyu player get on KGS and beat mogo in more than > 1 out of 10 games using this specific strategy.My guess is that if > your energy is spent setting up this trick, you will play weaker in general. i dunno. imagine one of the "mate in 20" types of sequences that you're supposed to learn when you first learn chess. imagine that you never learn how to deal with them. s. ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Thu, Mar 06, 2008 at 12:55:53PM +, Jacques Basaldúa wrote: > A 4-6 kyu human is behind by 10-15 points in the midgame (at that stage the > probability of winning is correlated with territory, so the MC bot is > building fine.) He creates a 12-16 point worth nakade trick in a corner > and does not solve it.The bot is happy, it thinks a bulk five is alive or > something like that. Perhaps the human sacrificed another 15 points > somewhere to create the trick so he should be dead lost. But, he only > has to play on, reduce, etc. As the endgame approaches, the MC bot > allows the reduction only until the territorial balance would change the > winner. The player is happy, he turned a 25 points loss into a 1.5 point > loss (assumed by the program) and has a 12 point surprise. > At the end, when the whole board is decided, the player kills > the bot's group and the bot turns a sure win into a sure loss and resigns. I honestly don't think at all that these "tricks" are created by the opponents meaningfully, in 90% of the cases I think they arise from perfectly natural corner situations; the nakade weakness is not that well known, I believe. > Because the trick can only be played by similar strength players (much > weaker players can't build something like that, much stronger don't need > it) > it affects the rating of the bots. I guess CrazyStone could be near KGS > 1dan > with that solved. It is 2k now. But, of course, the solution may not come > at > the price of making the program weaker. That is the difficult part. (Note that I believe CrazyStone played way too few games to have a precise rank. I think it could still be 3k and it could still be 1d as it is now, if it played more games. CzechBot has played thousands of games now I think, and its rank is _still_ evolving, though I don't think it will reach 2k.) -- Petr "Pasky" Baudis Whatever you can do, or dream you can, begin it. Boldness has genius, power, and magic in it.-- J. W. von Goethe ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Your idea is more in the spirit of MC, I like it. Another idea is borrowed from my first reasonable MC player. I looked at the "futures" of interesting move points and discouraged self-atari moves unless the future belonged to the player executing the move. (A "future" is the expected percentage of time a given player ended up with a given point at the end of the random games.) So some sort of pre-processed quick all-moves-as-first random play-out can give you a sense of which self-atari points are interesting. But it is not dynamic unfortunately and thus not scalable unless done periodically during the tree search. - Don Jonas Kahn wrote: >> I think the general outline is that you pre-test groups first to see if >> a self-atari move is "interesting."It's worthy of additional >> consideration if the stones it is touching have limited liberties and >> the group you self-atari is relatively small.Then you could go on to >> other tests which will consume even more time of course. >> > > > Here is an alternative, still in the line of gathering information from > play-outs. > > Do not turn down self-ataris TOO agressively. > When a self-atari occurs in play-out: > - notice which (and when). > - see if the self-ataried position is yours at the end (indeed it should > for a nakade). > If not: cancel the play-out (or start again from the moment you > self-ataried) Add a -1 to self-atarying at this place. > After say 10 (-1): strictly forbid this self-atari in future > playouts. > If yes: Remove all constraints on this self-atari (maybe give a bonus, > or study within the tree). > > Notice that this would also deal with seki: self-atari for both sides > getting completely forbidden at one point. > > Jonas > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
> Thanks for an excellent description of "the nakade > problem." I've found that it is easy for a "5kyu KGS > player" - myself - to exploit such situations. I can't > escape observing that endgame moves where a bot > permits me to take a yose point here, another there, > all the while drawing closer to a mythical 0.5 win in > it's mind, lead to the position where a miscalculation > about a group puts the program inescapably behind. > How do you know this is really happening? Do you have access to what the program is thinking? Could it be possible that the program knows it is lost the whole time?That's what it seems like to me from your description.Unless you calculated the exact score considering the nakade you can't really know that this is what happened. If you have access to the program logs, you would know, but I would be willing to bet that if you think that is what is going on, the program probably is lost and knows it - because you would get the same behavior. At the very least you wouldn't be able to tell either way. To get the evil nakade behavior, you have to have several events conspire to make this happen. You have to have a nakade pattern on the board somewhere, the score has to be close and in your favor considering the nakade, and the program has to believe that it is more advantageous to give away stones that not. Despite what many people believe, MC programs don't normally believe it's better to win small and they are not hell-bent on giving away stones in order to try to make the score come out to be exactly 0.5 win. Although it's easy to see that nakade is a problem, I agree with someone who said it takes a lot of skill to produce this.In fact, I believe that it cannot be done reliably by any player unless he is already much stronger than the program, in which case he doesn't "need" to do it in order to beat the program.(Indeed, it may be a counterproductive strategy if it distracts you from playing good moves.) Most MC programs won't just let you pick off points because that is normally a strategy that decreases your winning chances. They will only do that if every move leads to the same win or loss in every single play-out, or if the small win turns out to be easier to manage. I have to believe that this is not in general a "technique" to be used to consistently beat a MC program, it is more a tool of opportunity - you can probably set it up if everything is just right to begin with and/or the program stumbles into in more or less on it's own and loses because of it. I would love to see a 5kyu player get on KGS and beat mogo in more than 1 out of 10 games using this specific strategy.My guess is that if your energy is spent setting up this trick, you will play weaker in general. - Don > My hypothesis is that the computer is thinking the > group has a greater than 50% chance of living, but > this is true only if the computer plays a vital point > and/or the opponent fails to take that point. In > those cases, all playouts lead to a win for the > computer. But anyone about 8-10kyu is likely to spot > the vital point and take it, leading to a 100% loss > for the computer. > > >From observation, mid kyu players will set up these > situations and slay the computer with a high degree of > probability - say 80%. > >> A 4-6 kyu human is behind by 10-15 points in the >> midgame (at that stage the >> probability of winning is correlated with territory, >> so the MC bot is >> building fine.) He creates a 12-16 point worth >> nakade trick in a corner >> and does not solve it.The bot is happy, it thinks a >> bulk five is alive or >> something like that. Perhaps the human sacrificed >> another 15 points >> somewhere to create the trick so he should be dead >> lost. But, he only >> has to play on, reduce, etc. As the endgame >> approaches, the MC bot >> allows the reduction only until the territorial >> balance would change the >> winner. The player is happy, he turned a 25 points >> loss into a 1.5 point >> loss (assumed by the program) and has a 12 point >> surprise. >> At the end, when the whole board is decided, the >> player kills >> the bot's group and the bot turns a sure win into a >> sure loss and resigns. >> >> Because the trick can only be played by similar >> strength players (much >> weaker players can't build something like that, much >> stronger don't need >> it) >> it affects the rating of the bots. I guess >> CrazyStone could be near KGS >> 1dan >> with that solved. It is 2k now. But, of course, the >> solution may not >> come at >> the price of making the program weaker. That is the >> difficult part. >> > > > Terry McIntyre <[EMAIL PROTECTED]> > > “Wherever is found what is called a paternal government, there is found state > education. It has been discovered that the best way to insure implicit > obedience is to commence tyranny in the nursery.” > > Benjamin Disraeli, Speech in the House of Commons [J
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Because the trick can only be played by similar strength players (much weaker players can't build something like that, much stronger don't need it) it affects the rating of the bots. I guess CrazyStone could be near KGS 1dan with that solved. It is 2k now. But, of course, the solution may not come at the price of making the program weaker. That is the difficult part. I'm a 6k EGF player and I manage to win about 80% of the time against mogo and Leela on a [EMAIL PROTECTED] with 120min. (I only played 30 games each, so it may be a fluke, but...). If you ask me - on 19x19 dan status is far away. I think that Nakade will have to be solved before anything else. mfg Florian Erhardt ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
> I think the general outline is that you pre-test groups first to see if > a self-atari move is "interesting."It's worthy of additional > consideration if the stones it is touching have limited liberties and > the group you self-atari is relatively small.Then you could go on to > other tests which will consume even more time of course. Here is an alternative, still in the line of gathering information from play-outs. Do not turn down self-ataris TOO agressively. When a self-atari occurs in play-out: - notice which (and when). - see if the self-ataried position is yours at the end (indeed it should for a nakade). If not: cancel the play-out (or start again from the moment you self-ataried) Add a -1 to self-atarying at this place. After say 10 (-1): strictly forbid this self-atari in future playouts. If yes: Remove all constraints on this self-atari (maybe give a bonus, or study within the tree). Notice that this would also deal with seki: self-atari for both sides getting completely forbidden at one point. Jonas ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
steve uurtamo wrote: > yes, and the fact that turning a dumpling into a dead > group can take more than a few moves, since you may > have to fill up the eyespace several times, meaning > going fairly deeply down branches with several self-ataris > along the way. > Ok, it's pretty much as I thought. There are relatively simple solutions but they will slow down the play-outs significantly unless someone finds a creative fast solution. I think the general outline is that you pre-test groups first to see if a self-atari move is "interesting."It's worthy of additional consideration if the stones it is touching have limited liberties and the group you self-atari is relatively small.Then you could go on to other tests which will consume even more time of course. This is probably one of those changes necessary to improve the scaling curve. The slowdown will hurt at low levels and at some point it will break even, then be stronger. - Don > s. > > On Thu, Mar 6, 2008 at 9:23 AM, Don Dailey <[EMAIL PROTECTED]> wrote: > >> > >> > >> > You won't find that in computer vs computer games, because "tricking" the >> > strong programs requires some go skill and it only works if you wait long >> > enough before you "solve" the position. But if you search KGS (LeelaBot, >> > CrazyStone, CzechBot) for even games where the bot lost against a kyu >> > players you will find many. All go more or less like that: >> > >> > A 4-6 kyu human is behind by 10-15 points in the midgame (at that >> > stage the >> > probability of winning is correlated with territory, so the MC bot is >> > building fine.) He creates a 12-16 point worth nakade trick in a corner >> > and does not solve it.The bot is happy, it thinks a bulk five is alive or >> > something like that. Perhaps the human sacrificed another 15 points >> > somewhere to create the trick so he should be dead lost. But, he only >> > has to play on, reduce, etc. As the endgame approaches, the MC bot >> > allows the reduction only until the territorial balance would change the >> > winner. The player is happy, he turned a 25 points loss into a 1.5 point >> > loss (assumed by the program) and has a 12 point surprise. >> > At the end, when the whole board is decided, the player kills >> > the bot's group and the bot turns a sure win into a sure loss and >> > resigns. >> > >> > Because the trick can only be played by similar strength players (much >> > weaker players can't build something like that, much stronger don't >> > need it) >> > it affects the rating of the bots. I guess CrazyStone could be near >> > KGS 1dan >> > with that solved. It is 2k now. But, of course, the solution may not >> > come at >> > the price of making the program weaker. That is the difficult part. >> >> I want to make sure I understand the nakade problem, please correct me >> if I am wrong: >> >> My understanding of this is that many program do not allow self-atari >> moves in the play-outs because in general the overwhelming majority are >> stupid moves. Is that what is causing the nakade problem? And if >> you start including self-atari you weaken the program in general? >> >> And can I assume the tree portion is also inhibited from seeing this due >> to a combination of factors such as heuristics to delay exploring "ugly" >> moves as well as the weakness of the play-outs in this regard (which >> would cause the tree to not be inclined to get close enough to the issue >> to understand it properly?) >> >> - Don >> >> >> >> >> >> > >> > >> > Jacques. >> > ___ >> > computer-go mailing list >> > computer-go@computer-go.org >> > http://www.computer-go.org/mailman/listinfo/computer-go/ >> > >> ___ >> computer-go mailing list >> computer-go@computer-go.org >> http://www.computer-go.org/mailman/listinfo/computer-go/ >> >> > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
--- Jacques Basaldúa <[EMAIL PROTECTED]> wrote: > > Petr Baudis wrote: > > You won't find that in computer vs computer games, > because "tricking" the > strong programs requires some go skill and it only > works if you wait long > enough before you "solve" the position. But if you > search KGS (LeelaBot, > CrazyStone, CzechBot) for even games where the bot > lost against a kyu > players you will find many. All go more or less like > that: Thanks for an excellent description of "the nakade problem." I've found that it is easy for a "5kyu KGS player" - myself - to exploit such situations. I can't escape observing that endgame moves where a bot permits me to take a yose point here, another there, all the while drawing closer to a mythical 0.5 win in it's mind, lead to the position where a miscalculation about a group puts the program inescapably behind. My hypothesis is that the computer is thinking the group has a greater than 50% chance of living, but this is true only if the computer plays a vital point and/or the opponent fails to take that point. In those cases, all playouts lead to a win for the computer. But anyone about 8-10kyu is likely to spot the vital point and take it, leading to a 100% loss for the computer. >From observation, mid kyu players will set up these situations and slay the computer with a high degree of probability - say 80%. > A 4-6 kyu human is behind by 10-15 points in the > midgame (at that stage the > probability of winning is correlated with territory, > so the MC bot is > building fine.) He creates a 12-16 point worth > nakade trick in a corner > and does not solve it.The bot is happy, it thinks a > bulk five is alive or > something like that. Perhaps the human sacrificed > another 15 points > somewhere to create the trick so he should be dead > lost. But, he only > has to play on, reduce, etc. As the endgame > approaches, the MC bot > allows the reduction only until the territorial > balance would change the > winner. The player is happy, he turned a 25 points > loss into a 1.5 point > loss (assumed by the program) and has a 12 point > surprise. > At the end, when the whole board is decided, the > player kills > the bot's group and the bot turns a sure win into a > sure loss and resigns. > > Because the trick can only be played by similar > strength players (much > weaker players can't build something like that, much > stronger don't need > it) > it affects the rating of the bots. I guess > CrazyStone could be near KGS > 1dan > with that solved. It is 2k now. But, of course, the > solution may not > come at > the price of making the program weaker. That is the > difficult part. Terry McIntyre <[EMAIL PROTECTED]> Wherever is found what is called a paternal government, there is found state education. It has been discovered that the best way to insure implicit obedience is to commence tyranny in the nursery. Benjamin Disraeli, Speech in the House of Commons [June 15, 1874] Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
yes, and the fact that turning a dumpling into a dead group can take more than a few moves, since you may have to fill up the eyespace several times, meaning going fairly deeply down branches with several self-ataris along the way. s. On Thu, Mar 6, 2008 at 9:23 AM, Don Dailey <[EMAIL PROTECTED]> wrote: > > > > > > > > You won't find that in computer vs computer games, because "tricking" the > > strong programs requires some go skill and it only works if you wait long > > enough before you "solve" the position. But if you search KGS (LeelaBot, > > CrazyStone, CzechBot) for even games where the bot lost against a kyu > > players you will find many. All go more or less like that: > > > > A 4-6 kyu human is behind by 10-15 points in the midgame (at that > > stage the > > probability of winning is correlated with territory, so the MC bot is > > building fine.) He creates a 12-16 point worth nakade trick in a corner > > and does not solve it.The bot is happy, it thinks a bulk five is alive or > > something like that. Perhaps the human sacrificed another 15 points > > somewhere to create the trick so he should be dead lost. But, he only > > has to play on, reduce, etc. As the endgame approaches, the MC bot > > allows the reduction only until the territorial balance would change the > > winner. The player is happy, he turned a 25 points loss into a 1.5 point > > loss (assumed by the program) and has a 12 point surprise. > > At the end, when the whole board is decided, the player kills > > the bot's group and the bot turns a sure win into a sure loss and > > resigns. > > > > Because the trick can only be played by similar strength players (much > > weaker players can't build something like that, much stronger don't > > need it) > > it affects the rating of the bots. I guess CrazyStone could be near > > KGS 1dan > > with that solved. It is 2k now. But, of course, the solution may not > > come at > > the price of making the program weaker. That is the difficult part. > > I want to make sure I understand the nakade problem, please correct me > if I am wrong: > > My understanding of this is that many program do not allow self-atari > moves in the play-outs because in general the overwhelming majority are > stupid moves. Is that what is causing the nakade problem? And if > you start including self-atari you weaken the program in general? > > And can I assume the tree portion is also inhibited from seeing this due > to a combination of factors such as heuristics to delay exploring "ugly" > moves as well as the weakness of the play-outs in this regard (which > would cause the tree to not be inclined to get close enough to the issue > to understand it properly?) > > - Don > > > > > > > > > > > Jacques. > > ___ > > computer-go mailing list > > computer-go@computer-go.org > > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
> > > You won't find that in computer vs computer games, because "tricking" the > strong programs requires some go skill and it only works if you wait long > enough before you "solve" the position. But if you search KGS (LeelaBot, > CrazyStone, CzechBot) for even games where the bot lost against a kyu > players you will find many. All go more or less like that: > > A 4-6 kyu human is behind by 10-15 points in the midgame (at that > stage the > probability of winning is correlated with territory, so the MC bot is > building fine.) He creates a 12-16 point worth nakade trick in a corner > and does not solve it.The bot is happy, it thinks a bulk five is alive or > something like that. Perhaps the human sacrificed another 15 points > somewhere to create the trick so he should be dead lost. But, he only > has to play on, reduce, etc. As the endgame approaches, the MC bot > allows the reduction only until the territorial balance would change the > winner. The player is happy, he turned a 25 points loss into a 1.5 point > loss (assumed by the program) and has a 12 point surprise. > At the end, when the whole board is decided, the player kills > the bot's group and the bot turns a sure win into a sure loss and > resigns. > > Because the trick can only be played by similar strength players (much > weaker players can't build something like that, much stronger don't > need it) > it affects the rating of the bots. I guess CrazyStone could be near > KGS 1dan > with that solved. It is 2k now. But, of course, the solution may not > come at > the price of making the program weaker. That is the difficult part. I want to make sure I understand the nakade problem, please correct me if I am wrong: My understanding of this is that many program do not allow self-atari moves in the play-outs because in general the overwhelming majority are stupid moves. Is that what is causing the nakade problem? And if you start including self-atari you weaken the program in general? And can I assume the tree portion is also inhibited from seeing this due to a combination of factors such as heuristics to delay exploring "ugly" moves as well as the weakness of the play-outs in this regard (which would cause the tree to not be inclined to get close enough to the issue to understand it properly?) - Don > > > Jacques. > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
> Petr Baudis wrote: > >> MoGo can indeed play out some rather spectacular ko fights; > >> unfortunately, I couldn't find any quickly, so here is at least an > >> example of a shorter one. > I see you made the following comment in that game record, which seems > relevant to recent discussions here. > | mogo excels at reducing clear winning positions to close games they > | lose because of botched up tsumego > Is it mogo botching up the tsumego or its opponents? Do you have any > example game records for this? You won't find that in computer vs computer games, because "tricking" the strong programs requires some go skill and it only works if you wait long enough before you "solve" the position. But if you search KGS (LeelaBot, CrazyStone, CzechBot) for even games where the bot lost against a kyu players you will find many. All go more or less like that: A 4-6 kyu human is behind by 10-15 points in the midgame (at that stage the probability of winning is correlated with territory, so the MC bot is building fine.) He creates a 12-16 point worth nakade trick in a corner and does not solve it.The bot is happy, it thinks a bulk five is alive or something like that. Perhaps the human sacrificed another 15 points somewhere to create the trick so he should be dead lost. But, he only has to play on, reduce, etc. As the endgame approaches, the MC bot allows the reduction only until the territorial balance would change the winner. The player is happy, he turned a 25 points loss into a 1.5 point loss (assumed by the program) and has a 12 point surprise. At the end, when the whole board is decided, the player kills the bot's group and the bot turns a sure win into a sure loss and resigns. Because the trick can only be played by similar strength players (much weaker players can't build something like that, much stronger don't need it) it affects the rating of the bots. I guess CrazyStone could be near KGS 1dan with that solved. It is 2k now. But, of course, the solution may not come at the price of making the program weaker. That is the difficult part. Jacques. ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Wed, Mar 05, 2008 at 08:02:10PM +, Matthew Woodcraft wrote: > Petr Baudis wrote: > > MoGo can indeed play out some rather spectacular ko fights; > > unfortunately, I couldn't find any quickly, so here is at least an > > example of a shorter one. > > I see you made the following comment in that game record, which seems > relevant to recent discussions here. > > | mogo excels at reducing clear winning positions to close games they > | lose because of botched up tsumego > > Is it mogo botching up the tsumego or its opponents? Do you have any > example game records for this? MoGo, typically because of nakade. Note that it was kind of tongue-in-cheek comment since I can't really prove that MoGo would win any particular game if it did see the nakade, but here is an example where it wasted several dying-in-gote moves in a corner throughout the game. -- Petr "Pasky" Baudis Whatever you can do, or dream you can, begin it. Boldness has genius, power, and magic in it.-- J. W. von Goethe pasky-10.sgf Description: application/go-sgf ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Petr Baudis wrote: > MoGo can indeed play out some rather spectacular ko fights; > unfortunately, I couldn't find any quickly, so here is at least an > example of a shorter one. I see you made the following comment in that game record, which seems relevant to recent discussions here. | mogo excels at reducing clear winning positions to close games they | lose because of botched up tsumego Is it mogo botching up the tsumego or its opponents? Do you have any example game records for this? -M- ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
In message <[EMAIL PROTECTED]>, Petr Baudis <[EMAIL PROTECTED]> writes On Tue, Mar 04, 2008 at 12:01:02PM -0500, steve uurtamo wrote: cool. do you have any examples from a 19x19 game? that's what i was referring to when i said that i've never seen an MC player play out a ko fight. MoGo can indeed play out some rather spectacular ko fights; unfortunately, I couldn't find any quickly, so here is at least an example of a shorter one. Unfortunately, the 5d it is playing a six-stones game against plays a non-working threat in the end and loses. The ko fight starts at move 158. and ends at move 182, when MoGo recognises that the 5-dan's ko threat doesn't work, and connects the ko instead of answering it. I found this impressive. Nick -- Nick Wedd[EMAIL PROTECTED] ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
On Tue, Mar 04, 2008 at 12:01:02PM -0500, steve uurtamo wrote: > cool. do you have any examples from a 19x19 game? that's what > i was referring to when i said that i've never seen an MC player > play out a ko fight. MoGo can indeed play out some rather spectacular ko fights; unfortunately, I couldn't find any quickly, so here is at least an example of a shorter one. Unfortunately, the 5d it is playing a six-stones game against plays a non-working threat in the end and loses. The ko fight starts at move 158. -- Petr "Pasky" Baudis Whatever you can do, or dream you can, begin it. Boldness has genius, power, and magic in it.-- J. W. von Goethe pasky-8.sgf Description: application/go-sgf ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Quoting steve uurtamo <[EMAIL PROTECTED]>: cool. do you have any examples from a 19x19 game? that's what i was referring to when i said that i've never seen an MC player play out a ko fight. Valkyria is unfortunately way to weak for 19x19. My argument is more that in principle MC programs plays ko fights perfectly but not in complex positions,and most 19x19 games are complex. Actually one of my happiest moments of go programming was then my first MC-program played several kothreats in a 13x13 game. This surprised me because nothing in my program would "motivate" it to do so and I thought the search necessary to read it out was way beyond its capability but it was not. Then I realized that I no longer had to come up with some smart programming for ko and just could focus on other things. -Magnus ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
cool. do you have any examples from a 19x19 game? that's what i was referring to when i said that i've never seen an MC player play out a ko fight. thanks, s. On Tue, Mar 4, 2008 at 9:35 AM, Magnus Persson <[EMAIL PROTECTED]> wrote: > Attached is an sgf-game of a long kofight on 9x9 between Valkyria and > Gnugo. Valkyria of course wins with 0.5 otherwise it would probably > not have been such a nice example of a long kofight. > > -Magnus > > > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Attached is an sgf-game of a long kofight on 9x9 between Valkyria and Gnugo. Valkyria of course wins with 0.5 otherwise it would probably not have been such a nice example of a long kofight. -Magnus kofight318392.sgf Description: application/go-sgf ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
the thing that got me thinking about this is that i've never seen an MC player really play out a ko fight. (or perhaps they are in their own cryptic MC way that i can't see). The fact is that MoGo does play out? Ko fights. It actually plays Ko fights more often and somewhat better than 3-4 kyu human players. Don't forget the MC program strength is about 3-4 kyu, evaluated so far. It's still too early to talk about 9 dan level of playing. At the end of the day the playing strength of MC programs is limited by its equivalent search depth. Even locally MoGo's equivalent search depth is about 10 plys. Armed with the knowledge of joseki a 3 - 4 kyu human player can?often look?deeper than?10 plys. The search depth of MC programs in a whole board search is an open question. So is for 3 -4 kyu human players. DL ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
RE: Re : endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
If there is an illegal ko point on the board Many Faces includes ko threats in move generation, and it will play a ko threat if it is the best move found. So there is no special heuristic for ko other than generating more possible moves. David > -Original Message- > From: [EMAIL PROTECTED] [mailto:computer-go- > [EMAIL PROTECTED] On Behalf Of Gunnar Farnebäck > Sent: Monday, March 03, 2008 11:34 AM > To: computer-go > Subject: Re: Re : endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 > ?]) > > Don Dailey wrote: > > How do the classic programs handle these sequences of ko threats > that > > must be precisely calculated to extreme depths? > > Usually with big difficulty and crude heuristics. > > GNU Go determines that it should play a ko threat if the top move > turns out to be an illegal ko capture. In that case the top move is > removed from consideration and other moves are reevaluated by adding > the value of followup moves. After that the new top move is chosen, > which may be a ko threat if it's big enough and otherwise the > originally second move. > > The difficulty is of course to determine the followup value, which > tends not to be very exact at all, and far from all threats are found > in the first place. Still GNU Go can play ko decently, at least > compared to its general level of play. > > /Gunnar > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: Re : endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Don Dailey wrote: > How do the classic programs handle these sequences of ko threats that > must be precisely calculated to extreme depths? Usually with big difficulty and crude heuristics. GNU Go determines that it should play a ko threat if the top move turns out to be an illegal ko capture. In that case the top move is removed from consideration and other moves are reevaluated by adding the value of followup moves. After that the new top move is chosen, which may be a ko threat if it's big enough and otherwise the originally second move. The difficulty is of course to determine the followup value, which tends not to be very exact at all, and far from all threats are found in the first place. Still GNU Go can play ko decently, at least compared to its general level of play. /Gunnar ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
ah, sorry to respond to my own post, but of course if the game is close, the threat doesn't even need to be of value > X, if it is large enough to threaten to win the game, which can happen in near-endgame situations. the idea is that you start a ko for something that your opponent is absolutely unwilling to give up (because it would lose the game), and for which you have no expectation of being able to win that fight, you can still either get small compensation (by making an unanswered tiny threat) or big compensation (by making a threat that if unanswered would lose the game). so simply having these threats lying around in the bank can be quite profitable if they're used correctly. games are sometimes resigned as soon as one player realizes that he doesn't have enough ko threats to win a ko fight, if it's for enough points. but as you mentioned earlier, sometimes MC players abandon the fight because something else looks more interesting. this is fairly rare behavior in human games, which is why i noticed it of these (MC) players. s. On Mon, Mar 3, 2008 at 12:37 PM, steve uurtamo <[EMAIL PROTECTED]> wrote: > the general idea is that if the ko represents something of value X, > then making threats of value > X will force your opponent to answer, > and if he does not have as many threats of value > X as you do, then > you can eventually win the ko fight (by filling the ko) and gain X-(value of > sente) points, or have a threat unanswered and gain (> X - X) points, > along with > possibly taking sente (which could be worth something near to X, but is > probably smaller). > > this is really relevant when X is large, or when there are multiple kos on > the board of varying values. > > important kos are often at a critical connection point for one or both > players, or at a critical eyespace (such as in the corner or along the edge) > > strong players can crush weaker players simply by starting kos in > important places because they know that they can win the ko or gain > points in compensation for starting a ko, since ko fights are generally > very hard for weaker players, who usually misjudge the value of ko > threats, remove ko threats early in the game for no good reason, or > have difficulty finding (or creating a sequence of!) reasonably-valued > ko threats. > > s. > > > > On Mon, Mar 3, 2008 at 8:49 AM, Don Dailey <[EMAIL PROTECTED]> wrote: > > > > > > > > steve uurtamo wrote: > > >> So I don't think > > >> sophisticated ko fights are resolved but I not strong enough to really > > >> quantify this. > > >> > > > > > > It's very often the case that games between, say, two 7d players on KGS > > > will come down, in large part, to one or two or three ko fights and > their > > > resolution. or even the threat of a ko fight if one player is weak > enough. i'm > > > not sure that even the strongest amateurs count all of their ko threats > > > correctly ahead of playing them (the game is quite dynamic, after all) > but > > > this is way, way deeper water than i tread in, so i don't have any real > idea. > > > > > > i just wonder if anyone has tried to beat these programs by initiating a > > > complicated but critical ko fight. i'd think it'd be a can't-lose if > you chose > > > it correctly. i wonder if it's a repeatable way to beat these guys, or > if the > > > depth is handled just fine. > > > > > > the thing that got me thinking about this is that i've never seen an MC > > > player really play out a ko fight. (or perhaps they are in their own > cryptic > > > MC way that i can't see). > > > > > Perhaps I don't know what I'm talking about here, but is it possible > > that most ko fights can be avoided?Perhaps ko fights introduce too > > much uncertainty and they look for a more simple way to proceed? > > I've seen lot's of positions where there is a ko back and forth 2 or 3 > > times and the computer used every other turn to do something > > constructive in some particular area - then when it stopped fighting it > > stayed interested in that other area. I don't really know if what I > > saw meant anything - it involved only 1 ko point.Is that still > > considered a ko fight? It "seemed" to me to know what it was doing, > > picking (what seemed to me) just the right moment to abandon the ko. > > > > - Don > > > > > > > > > s. > > > ___ > > > computer-go mailing list > > > computer-go@computer-go.org > > > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > > > > > > ___ > > computer-go mailing list > > computer-go@computer-go.org > > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
the general idea is that if the ko represents something of value X, then making threats of value > X will force your opponent to answer, and if he does not have as many threats of value > X as you do, then you can eventually win the ko fight (by filling the ko) and gain X-(value of sente) points, or have a threat unanswered and gain (> X - X) points, along with possibly taking sente (which could be worth something near to X, but is probably smaller). this is really relevant when X is large, or when there are multiple kos on the board of varying values. important kos are often at a critical connection point for one or both players, or at a critical eyespace (such as in the corner or along the edge) strong players can crush weaker players simply by starting kos in important places because they know that they can win the ko or gain points in compensation for starting a ko, since ko fights are generally very hard for weaker players, who usually misjudge the value of ko threats, remove ko threats early in the game for no good reason, or have difficulty finding (or creating a sequence of!) reasonably-valued ko threats. s. On Mon, Mar 3, 2008 at 8:49 AM, Don Dailey <[EMAIL PROTECTED]> wrote: > > > > steve uurtamo wrote: > >> So I don't think > >> sophisticated ko fights are resolved but I not strong enough to really > >> quantify this. > >> > > > > It's very often the case that games between, say, two 7d players on KGS > > will come down, in large part, to one or two or three ko fights and their > > resolution. or even the threat of a ko fight if one player is weak > enough. i'm > > not sure that even the strongest amateurs count all of their ko threats > > correctly ahead of playing them (the game is quite dynamic, after all) but > > this is way, way deeper water than i tread in, so i don't have any real > idea. > > > > i just wonder if anyone has tried to beat these programs by initiating a > > complicated but critical ko fight. i'd think it'd be a can't-lose if you > chose > > it correctly. i wonder if it's a repeatable way to beat these guys, or if > the > > depth is handled just fine. > > > > the thing that got me thinking about this is that i've never seen an MC > > player really play out a ko fight. (or perhaps they are in their own > cryptic > > MC way that i can't see). > > > Perhaps I don't know what I'm talking about here, but is it possible > that most ko fights can be avoided?Perhaps ko fights introduce too > much uncertainty and they look for a more simple way to proceed? > I've seen lot's of positions where there is a ko back and forth 2 or 3 > times and the computer used every other turn to do something > constructive in some particular area - then when it stopped fighting it > stayed interested in that other area. I don't really know if what I > saw meant anything - it involved only 1 ko point.Is that still > considered a ko fight? It "seemed" to me to know what it was doing, > picking (what seemed to me) just the right moment to abandon the ko. > > - Don > > > > > s. > > ___ > > computer-go mailing list > > computer-go@computer-go.org > > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > > > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Stronger players often initiate sequences where the life of a group depends on ko. I don't know if this sort of thing happens in MC games, or if MC players can deal with it effectively. Terry McIntyre <[EMAIL PROTECTED]> Wherever is found what is called a paternal government, there is found state education. It has been discovered that the best way to insure implicit obedience is to commence tyranny in the nursery. Benjamin Disraeli, Speech in the House of Commons [June 15, 1874] Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
> the thing that got me thinking about this is that i've never seen an MC > player really play out a ko fight. (or perhaps they are in their own cryptic > MC way that i can't see). Well this could easily be solved by *always* investigating moves that take (or create) a ko. This of course will force the program to actually *recognise* the ko's. A sloppy way to "always investigate" would be to "always try moves that capture". A similar approach can be used for ladders. Perhaps snapbacks can be handled this way, too. Not sure. Some "classical" programs return "special values" in their evaluation function, such as "can win, but needs ko(s)". This outcome can be used to steer the upper parts of the programs. IIRC there is some stuff about this on Dave Dyer's website. HTH, AvK ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Quoting steve uurtamo <[EMAIL PROTECTED]>: the thing that got me thinking about this is that i've never seen an MC player really play out a ko fight. (or perhaps they are in their own cryptic MC way that i can't see). It takes two to dance a Tango! For example ko fights on 9x9 occur late in the game so often the ko does not matter and both programs know it. Or both programs knows who is going to win the fight and the losing program will try to do something else. In other words: If a human player plays the losing side I think most strong MC-programs will play correctly if the ko-fight is necessary to win. Of course as always this depends on how deep the program searches and the complexity of the situation. But in my experience ko fights is not a special weakness of MC-programs it is just one of many kinds of tactical complexity that the tree-part search has to deal with. Still it is an interesting question if there are some good simple tricks one can use in the playouts to make the program play even stronger in ko fights. -Magnus ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
steve uurtamo wrote: >> So I don't think >> sophisticated ko fights are resolved but I not strong enough to really >> quantify this. >> > > It's very often the case that games between, say, two 7d players on KGS > will come down, in large part, to one or two or three ko fights and their > resolution. or even the threat of a ko fight if one player is weak enough. > i'm > not sure that even the strongest amateurs count all of their ko threats > correctly ahead of playing them (the game is quite dynamic, after all) but > this is way, way deeper water than i tread in, so i don't have any real idea. > > i just wonder if anyone has tried to beat these programs by initiating a > complicated but critical ko fight. i'd think it'd be a can't-lose if you > chose > it correctly. i wonder if it's a repeatable way to beat these guys, or if the > depth is handled just fine. > > the thing that got me thinking about this is that i've never seen an MC > player really play out a ko fight. (or perhaps they are in their own cryptic > MC way that i can't see). > Perhaps I don't know what I'm talking about here, but is it possible that most ko fights can be avoided?Perhaps ko fights introduce too much uncertainty and they look for a more simple way to proceed? I've seen lot's of positions where there is a ko back and forth 2 or 3 times and the computer used every other turn to do something constructive in some particular area - then when it stopped fighting it stayed interested in that other area. I don't really know if what I saw meant anything - it involved only 1 ko point.Is that still considered a ko fight? It "seemed" to me to know what it was doing, picking (what seemed to me) just the right moment to abandon the ko. - Don > s. > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
> So I don't think > sophisticated ko fights are resolved but I not strong enough to really > quantify this. It's very often the case that games between, say, two 7d players on KGS will come down, in large part, to one or two or three ko fights and their resolution. or even the threat of a ko fight if one player is weak enough. i'm not sure that even the strongest amateurs count all of their ko threats correctly ahead of playing them (the game is quite dynamic, after all) but this is way, way deeper water than i tread in, so i don't have any real idea. i just wonder if anyone has tried to beat these programs by initiating a complicated but critical ko fight. i'd think it'd be a can't-lose if you chose it correctly. i wonder if it's a repeatable way to beat these guys, or if the depth is handled just fine. the thing that got me thinking about this is that i've never seen an MC player really play out a ko fight. (or perhaps they are in their own cryptic MC way that i can't see). s. ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: Re : endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
How do the classic programs handle these sequences of ko threats that must be precisely calculated to extreme depths? - Don steve uurtamo wrote: > the issue with ko is the order in which the ko threats are played, > which can only be successfully evaluated if the average playout > finishes the ko correctly. > > s. > > On Sun, Mar 2, 2008 at 4:56 PM, ivan dubois <[EMAIL PROTECTED]> wrote: > >> Ok, I think I see what you mean, but I am not sure I really agree. >> As you say, this is related to horizon effect. I think current MC programs >> can play ko quite well because they are trying do delay the outcome of >> losing the ko, therefore they tend to play threats do gain time, just like >> human players do. I dont think it is essential that the ko be resolved >> inside the tree part. And I dont believe there exist efficient way to handle >> ko in the playout other than just fordiding simple ko recapture. >> >> Ivan >> >> - Message d'origine >> De : Jonas Kahn <[EMAIL PROTECTED]> >> À : computer-go >> Envoyé le : Dimanche, 2 Mars 2008, 21h32mn 43s >> Objet : Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?]) >> >> > But correct ko threats playing has nothing to do with the playout part : >> Since it is a strategic concept that involves global understanting, It is >> handled by the UCT tree part. >> >> Yes and no. >> Theoretically, that's the work of the UCT part. But, as Steve pointed >> out, kos can go on for long. I don't know what depth is attained in the >> tree (by the way, I would really like to know), but I doubt it is that >> long. Moreover, some kos must be kept for later. >> >> Hence, some basic understanding of kos in the playouts might be useful. >> >> That's merely a variation of the horizon effect. We could even imagine a >> situation where the UCT makes a threat that loses points in the only aim >> of having the ko past the horizon, where it would be 50-50 (for example) >> in the playout. >> >> Jonas >> ___ >> computer-go mailing list >> computer-go@computer-go.org >> http://www.computer-go.org/mailman/listinfo/computer-go/ >> >> >> >> >> _ >> Ne gardez plus qu'une seule adresse mail ! Copiez vos mails vers Yahoo! >> Mail http://mail.yahoo.fr >> ___ >> computer-go mailing list >> computer-go@computer-go.org >> http://www.computer-go.org/mailman/listinfo/computer-go/ >> >> > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Jonas Kahn wrote: >> But correct ko threats playing has nothing to do with the playout part : >> Since it is a strategic concept that involves global understanting, It is >> handled by the UCT tree part. >> > > Yes and no. > Theoretically, that's the work of the UCT part. But, as Steve pointed > out, kos can go on for long. I don't know what depth is attained in the > tree (by the way, I would really like to know), but I doubt it is that > long. Moreover, some kos must be kept for later. > The depth of the principal variation (the printed line) can be very impressive, but it's only seeing a fraction of the real tree and I don't think the quality of this line of play compares to the quality in other games doing alpha/beta with good evaluation. So I don't think sophisticated ko fights are resolved but I not strong enough to really quantify this. As I've state before, you can find certain things that programs do really well (better than people of similar strength) and things they are weak at and you can try to draw conclusions from that but you will probably be wrong since it's outside our normal experience. - Don > Hence, some basic understanding of kos in the playouts might be useful. > > That's merely a variation of the horizon effect. We could even imagine a > situation where the UCT makes a threat that loses points in the only aim > of having the ko past the horizon, where it would be 50-50 (for example) > in the playout. > > Jonas > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: Re : endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
the issue with ko is the order in which the ko threats are played, which can only be successfully evaluated if the average playout finishes the ko correctly. s. On Sun, Mar 2, 2008 at 4:56 PM, ivan dubois <[EMAIL PROTECTED]> wrote: > Ok, I think I see what you mean, but I am not sure I really agree. > As you say, this is related to horizon effect. I think current MC programs > can play ko quite well because they are trying do delay the outcome of losing > the ko, therefore they tend to play threats do gain time, just like human > players do. I dont think it is essential that the ko be resolved inside the > tree part. And I dont believe there exist efficient way to handle ko in the > playout other than just fordiding simple ko recapture. > > Ivan > > - Message d'origine > De : Jonas Kahn <[EMAIL PROTECTED]> > À : computer-go > Envoyé le : Dimanche, 2 Mars 2008, 21h32mn 43s > Objet : Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?]) > > > But correct ko threats playing has nothing to do with the playout part : > Since it is a strategic concept that involves global understanting, It is > handled by the UCT tree part. > > Yes and no. > Theoretically, that's the work of the UCT part. But, as Steve pointed > out, kos can go on for long. I don't know what depth is attained in the > tree (by the way, I would really like to know), but I doubt it is that > long. Moreover, some kos must be kept for later. > > Hence, some basic understanding of kos in the playouts might be useful. > > That's merely a variation of the horizon effect. We could even imagine a > situation where the UCT makes a threat that loses points in the only aim > of having the ko past the horizon, where it would be 50-50 (for example) > in the playout. > > Jonas > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > > > _ > Ne gardez plus qu'une seule adresse mail ! Copiez vos mails vers Yahoo! Mail > http://mail.yahoo.fr > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re : endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Ok, I think I see what you mean, but I am not sure I really agree. As you say, this is related to horizon effect. I think current MC programs can play ko quite well because they are trying do delay the outcome of losing the ko, therefore they tend to play threats do gain time, just like human players do. I dont think it is essential that the ko be resolved inside the tree part. And I dont believe there exist efficient way to handle ko in the playout other than just fordiding simple ko recapture. Ivan - Message d'origine De : Jonas Kahn <[EMAIL PROTECTED]> À : computer-go Envoyé le : Dimanche, 2 Mars 2008, 21h32mn 43s Objet : Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?]) > But correct ko threats playing has nothing to do with the playout part : > Since it is a strategic concept that involves global understanting, It is > handled by the UCT tree part. Yes and no. Theoretically, that's the work of the UCT part. But, as Steve pointed out, kos can go on for long. I don't know what depth is attained in the tree (by the way, I would really like to know), but I doubt it is that long. Moreover, some kos must be kept for later. Hence, some basic understanding of kos in the playouts might be useful. That's merely a variation of the horizon effect. We could even imagine a situation where the UCT makes a threat that loses points in the only aim of having the ko past the horizon, where it would be 50-50 (for example) in the playout. Jonas ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/ _ Ne gardez plus qu'une seule adresse mail ! Copiez vos mails vers Yahoo! Mail http://mail.yahoo.fr ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
> But correct ko threats playing has nothing to do with the playout part : > Since it is a strategic concept that involves global understanting, It is > handled by the UCT tree part. Yes and no. Theoretically, that's the work of the UCT part. But, as Steve pointed out, kos can go on for long. I don't know what depth is attained in the tree (by the way, I would really like to know), but I doubt it is that long. Moreover, some kos must be kept for later. Hence, some basic understanding of kos in the playouts might be useful. That's merely a variation of the horizon effect. We could even imagine a situation where the UCT makes a threat that loses points in the only aim of having the ko past the horizon, where it would be 50-50 (for example) in the playout. Jonas ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
i'm just saying (and perhaps i'm misunderstanding something here) that lots of playout depth, and therefore lots of simulations are required to see *any* advantage to playing out a ko. s. On Sun, Mar 2, 2008 at 3:17 PM, ivan dubois <[EMAIL PROTECTED]> wrote: > Mogo is already very strong at endgame and certainly plays perfectly near the > end of the game. The more advanced the program, the sooner it can play > perfect endgame. > But correct ko threats playing has nothing to do with the playout part : > Since it is a strategic concept that involves global understanting, It is > handled by the UCT tree part. > > - Message d'origine > De : steve uurtamo <[EMAIL PROTECTED]> > À : computer-go > Envoyé le : Dimanche, 2 Mars 2008, 20h25mn 33s > Objet : Re: [computer-go] Re: Should 9x9 komi be 8.0 ?] > > a few subtleties -- > > it's possible for a machine to play a perfect endgame, and my > guess is that machines will play perfect endgames before people > do, although most pros are excellent at the endgame. > > counting ko threats and utilizing kos effectively is tricky in playouts -- > kos can naturally extend a playout very, very far beyond where the > actual advantage would be taken in a non-ko situation, and the likelihood > of getting this far often enough in playouts to see the advantage is going > to be difficult for machines without a lot of domain-specific knowledge. > > different humans are often good at different stages of the game, and > making up a few points in the endgame, or getting a massive lead in > the beginning of the game may be possible, convincing a computer > player of something that isn't true -- either that it's nearly guaranteed > to win, or nearly guaranteed to lose. > > all that having been said, i'm quite impressed with how well these programs > are doing. > > s. > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > > > _ > Ne gardez plus qu'une seule adresse mail ! Copiez vos mails vers Yahoo! Mail > http://mail.yahoo.fr > ___ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
endgame (Was [computer-go] Re: Should 9x9 komi be 8.0 ?])
Mogo is already very strong at endgame and certainly plays perfectly near the end of the game. The more advanced the program, the sooner it can play perfect endgame. But correct ko threats playing has nothing to do with the playout part : Since it is a strategic concept that involves global understanting, It is handled by the UCT tree part. - Message d'origine De : steve uurtamo <[EMAIL PROTECTED]> À : computer-go Envoyé le : Dimanche, 2 Mars 2008, 20h25mn 33s Objet : Re: [computer-go] Re: Should 9x9 komi be 8.0 ?] a few subtleties -- it's possible for a machine to play a perfect endgame, and my guess is that machines will play perfect endgames before people do, although most pros are excellent at the endgame. counting ko threats and utilizing kos effectively is tricky in playouts -- kos can naturally extend a playout very, very far beyond where the actual advantage would be taken in a non-ko situation, and the likelihood of getting this far often enough in playouts to see the advantage is going to be difficult for machines without a lot of domain-specific knowledge. different humans are often good at different stages of the game, and making up a few points in the endgame, or getting a massive lead in the beginning of the game may be possible, convincing a computer player of something that isn't true -- either that it's nearly guaranteed to win, or nearly guaranteed to lose. all that having been said, i'm quite impressed with how well these programs are doing. s. ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/ _ Ne gardez plus qu'une seule adresse mail ! Copiez vos mails vers Yahoo! Mail http://mail.yahoo.fr ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
