terry mcintyre wrote: > Ladders are not hard, especially if one is permitted to place stones > on the (virtual) board to trace the flow. A 20 kyu human can follow > the logic. > > Don, you describe some subtle choices of playing one's opponent, and > compare them to MC programs, but you are a fairly strong chess player. > If you were counseling a beginner, you'd surely urge him/her to focus > on getting the basics right before getting fancy with estimations of > winning probability vis a vis particular opponents. For beginners I would strongly council to play the board, not the opponent.
At the top level it's not really like this. You must play soundly but there is a huge element of playing the opponent. The most basic winning technique is to constantly present problems to your opponent - even though this may have little to do with the game theoretic score. Part of the reason for this is that if you do it to him, he is too busy to hurt you. But the real point is that you want to provoke an error. If you don't play this way at the higher level most games would end in a draw. 2700 players do not want to draw 2500 players too much so must play provocatively. Top level players tend to draw each other a lot unless the results are very important - and even then it's difficult to get out of a draw. Here is some advice for playing against stronger players: Don't change your game. Play the same way you normally would. If you like tactics, don't be afraid to mix it up. It's not that this is likely to give you a win, but it's certainly not going the help you to change your style. When your opponent is in time pressure, naive players start playing really fast in order to add to their opponents time pressure. This is a really stupid mistake. You are giving away your only advantage, the fact that you have more time than your opponent. Duhhh!!!!! In fact, there might even be some benefit to playing a little slower than usual. In time pressure your opponent has the advantage of the adrenalin in his system and it actually helps him. But you cannot maintain an adrenalin rush for too long without it washing you out. So if he has 1 minute on his clock, you can keep his adrenalin going for 20 minutes he will be exhausted before long. Many mistakes are made immediately after time-control has been reach and the player thinks he is safe. All of these things are attempts to play the opponent and it usually turns out that this is foolish. You are upsetting and distracting yourself from the game when you do this and only if you really know what you are doing should playing the opponent be attempted. > > Go and chess differ in a fundamental way. With chess, many positions > may be genuinely unknowable, beyond human/machine ability to measure > the exact outcome; a probabilistic approach may be well suited to such > situations. With Go, there are many situations which can be read out > precisely, provided that one has the proper tools - ladders, the > ability to distinguish between one and two eyes; the ability to reduce > eyespaces to a single eye with an appropriate placement; and so forth. > Failure to recognize such situations is like failing to spot a pinned > piece or a passed pawn. But so far, the evidence says the probabilistic approach works in GO and so far nobody has demonstrated a strong chess program that uses this approach. However I don't know if anyone has seriously tried in chess. > > Every now and then, I have the opportunity to play a pro, or watch a > pro against other amateur players. Even 4 and 5 dan amateurs find > their groups crumbling against pro players. But in many cases, the pro > simply exploits weak shape - reducing groups to the "one eyed state." > > Evaluating winning odds depends upon evaluating the final score at the > leaf nodes, which depends on being able to distinguish between one and > two eyes, to count liberties in capturing races, to recognize seki, to > read ladders, and other basic skills. At some point in the game, an > evaluation function should be able to quickly and accurately report > "oops, just lost ten or twenty points, with no compensating gain, > therefore the score is -15; this node should be reported as a lost > game, back up and try something different." The earlier one can make > such accurate assessments, the better one's game. > I am a lousy go player, but I started out counting stones, trying to win everything. I think I definitely made a step forward when I started mentally mapping out the board. I actually learned this from my own monte carlo program. I try to figure out exactly what I need to win and then I focus on that. That doesn't mean you are not flexible and opportunistic - if I have a chance to grab a piece I didn't expect, it's that much less I have to worry about elsewhere. Then at some point I consolidate, making sure if I'm winning I don't attempt any foolish excursions. Instead I strengthen what I have a seal off everything that could come back to bite me later. If I'm losing, I try to get appropriately desperate and will try any speculative attack that has some chance. I have heard that really good players play like this too (only far better than I do.) > > > ------------------------------------------------------------------------ > Never miss a thing. Make Yahoo your homepage. > <http://us.rd.yahoo.com/evt=51438/*http://www.yahoo.com/r/hs> > ------------------------------------------------------------------------ > > _______________________________________________ > computer-go mailing list > [email protected] > http://www.computer-go.org/mailman/listinfo/computer-go/ _______________________________________________ computer-go mailing list [email protected] http://www.computer-go.org/mailman/listinfo/computer-go/
