Hi Matt, What you wrote is well thought out. I give some comments.
On Mon, 2007-01-22 at 11:27 -0600, Matt Gokey wrote: > Been following this thread pretty closely and thought I would jump in > with a thought and try to find some common ground. I think there is > truth to be found in both sides of this argument. > > Of course people improve with time and so do computers with certain > algorithms. The question is about the curve and whether there is a > significant difference in this curve between chess and go. > > Don believes there is probably no difference and states a rule: doubling > thinking time = linear improvement in play. To a point the improvement is linear - however there is gradual curve to this so it's not completely linear. The surprise in computer chess was that it was difficult to detect that a doubling was NOT completely linear and only when computers really became strong did it start to become clear there was a gradual tapering off. I believe the same curve exists in a properly scaled GO program but since the game is deeper I believe it will appear linear for a long time to come, but in fact it's not strictly linear. I would also like to point out that although I believe that each doubling is roughly linear, I'm not claiming you get the same improvement as in chess. You might get more or you might get less - actually the evidence is that you get more, perhaps because the game is much longer and minor improvements over hundreds of move add up to more likelihood of a win. > What if we look at it mathematically by looking at the branching factor? > Go’s branching factor is generally considered to be about an order of > magnitude greater than chess – perhaps a bit less, right? That means > that after each ply go becomes another additional order of magnitude > more complex. Now of course, in practice it’s not so simple, as > breaking the game into regions and doing local reading and global > analysis reduces the complexity somewhat, but in general go explodes a > lot faster than chess and this fact is commonly used as one of the > reasons methods used for computer chess don’t work on go especially > combined with the lack of reliable evaluation. I think this is more about information, not brute force ply. With twice as much time you have twice as many thoughts, twice as much time to produce a better idea, twice everything. I also suspect it's about playing the odds. Give me twice as much time to think about something interesting and challenging, and it "increases my chances" of having a meaningful insight. It's always tempting to simply compare to depth or ply but I don't think it's about that. When I talk about scalable algorithms instantly search comes to mind - but we can be open about this. Who is to say some other scalable algorithm will not come along? Perhaps some iterative computation that systematically produces (on average) a better and better move. I'm winging it here, but I can imagine some proof procedure, where you consider each move on the board and systematically prove that one move cannot be as good as another - playing the elimination game. Or perhaps a similar iterative procedure that can do this in stages with probabilities. (It's starting to sound suspiciously like UCT.) But my point is that this is about information processing, not ply depth although there may be a great deal of overlap. > For the sake of argument if we assume that doubling thinking time allows > one to double the number of positions and alternatives that can be > analyzed, this doubling would seem to have lesser impact in go where the > explosion is much quicker than in chess and thus the same relationship > may not hold. It's not clear to me that the effective branching factor is that much higher. Right now it is for computers, but for a good player most of the garbage is pruned and the tree is very narrow. But even if I'm wrong about this, you must remember that for ELO purposes it's more about how much information you can process relative to your opponent, not how close you can get to perfect play. Maybe that's why there is so much confusion about this. > The improvement may not be linear or it may not hold for > very long. The point of diminishing returns for a human due to this > could be much earlier in go than in chess. I actually believe the point of diminishing returns in GO to be much more extended than in chess because the game is deeper strategically. > As go players get better > they must learn to “sense” the board based on years of experience > combined with our evolutionary tuned super parallel visual pattern > matcher. This provides the player shortcuts that otherwise would be > impossible (for humans) to read out. Assuming enough processing power > and memory this problem would not necessarily hold for computer-go. By > the way, I think some of this very same thing applies to both chess and > go, just a matter of different degrees. This it of course needed for strong play - but I'm arguing that it's not for scalability. There is however some evidence (in chess) that the more skilled you are, the more scalable you can be. Hans Berliner did a huge rating experiment with 2 versions of his world class program, one with simple dumb evaluation and one with high quality evaluation. He showed that the smarter program improved more quickly as he continued to bump up the level. I think several people hinted at this on this group. Better players have better mental machinery to work with the extra time - I don't have a problem with this concept. I think this probably also produces intransitives in playing strength, where a weak player with extra time appears to improve at a more rapid pace when measured against another weak player, but it only partially translates to extra strength against strong players. > From my own experience with chess and go, I can say that I don’t feel > overwhelmed when playing chess. I always felt overwhelmed even though I nearly reached USCF expert level or what was called candidate master strength. I don't feel any different in GO although I lack experience. When I play against my programs I always feel like I could play a better move given more time and I never feel like I've run out of things to think about. I think a stronger player might realize more situations where the right move is obvious, but he will still encounter plenty of situations where he would like to have more time. As has been pointed out, the strongest go players will spend huge amounts of time on key critical moves. In a way, chess is easier and there are many more obvious choices to make in my opinion. The obvious recapture comes to mind. There were always lots of moves in my games where I was quite confident that I could play the right move without needed a lot of time. However that doesn't make it non-scalable. > That is, I always feel like I can think > and reason about the moves fairly deeply and use simple evaluation like > piece counts, protection, mobility, etc. to decide between lines of > play. I may be entirely wrong but I feel like I can think about it > anyway. I had more trouble with strategic decisions than tactics. You can usually reason out tactics fairly quickly and I never felt that was where the time should be invested. For me it was about making the right decisions - will an attack eventually work? Should I go for this kind of ending or that? Should I trade queens, expand my sphere of influence, etc. But it doesn't matter. Whatever you do it helps to have more time and I don't believe it's only about calculating tactical sequences. > I’m not a real strong player, but I had a friend in high school > and college whose Dad was a Grand Master. His son was pretty good and > we would play a lot of chess together. Once in while I would play > against his Dad and usually get slaughtered. One time he was doing one > of those events where he would play 30 people at once. I played and > managed to keep him challenged well into the middle game. I could tell > he was worried. On one trip around I still hadn’t made my move and was > forced to make the best one I had. It was a blunder but I didn’t see it > yet. Immediately he took advantage of it and I didn’t have a chance > after that. He confirmed this after the game was over and set the > pieces up as they were at that point and showed me what I should have > done (I thought an amazing feat given he was playing 30 or more > different simultaneous games). Anyway in this situation where I had a > lot more time than he did I was able to challenge him and only after > making a blunder was I in trouble. So I see where Don is coming from > with Chess. There is a very obvious and clear strength curve in Chess for humans as a function of time. There is no question about this and it has been shown in postal play, speed-chess, tournament games, etc. As I mentioned before you can compare directly to computers given more and more time and see that humans pull ahead (or catch up) given more and more time even though computers improve significantly with time. > Now with Go as a beginner still, on the other hand, I almost always felt > and still feel quite overwhelmed without enough tools to understand how > to plan and evaluate moves in all but the simplest isolated cases. I > know that giving me tons of extra time against a good player would not > help. There is a ton of difference between whether it would help, and whether it would help enough to give you a realistic chance of winning. If you are playing someone a few stones stronger where your odds of winning are 1 in a million, then you are going to feel overwhelmed (and will probably lose) even given a LOT of extra time. This is another human perception issue. If you could increase your odds from 1 in a million to 1 in a thousand, that's a huge improvement. Just because it's not nearly enough doesn't take away from the fact that your odds of winning have increased by a factor of 1000! But most people have no feel for small odds (and is why people continue to smoke cigarettes for example, though know intellectually that it's killing them, but it's happening so slowly that it doesn't seem like it's happening at all.) If everyone was granted immortality where you would never die of natural causes or disease, would you stop driving automobiles? I'll bet most wouldn't, but I would. To stop driving a car might extend my life expectancy by a few thousand years. Eventually we would all succumb to a stupid freak accident and die, but littele behaviors that we don't consider all that dangerous might easily make the difference between those who live a few hundred years and those who live a few thousand. Playing games is like this. Increase your chances of not making a blunder just slightly on every move, and move up a rank. Increase you chances of finding a better in a few positions, and move up another rank. > The interactions between areas and the explosion of the game and > lack of experience to be able to “sense” good shape and proper balance > early enough to lead to life and territory just simply overwhelms me. > The feeling is not as severe as it was when I first learned, but it is > still there. I wonder whether even for strong amateurs this is still > the case, but just happens a bit deeper. Is this the time limit that > Ray talks about where any more time is not helpful? It is that point > when it becomes so terribly complex and overwhelming that no more > thinking can help given your current ability to judge potential in the > positions. No, I believe this is nonsense. You don't have to go from being completely overwhelmed and in the dark to having it all figured out with confidence to move up a rank. All you have to do is make slightly better decisions a few time per game to play better. Extra time give you this. - Don > _______________________________________________ > 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/
