From: Larry Kaufman WIZARD NET> Date: 13 may 1997 Subject: Re: Real chess computing At 01:23 PM 5/13/97 -0400, you wrote: >Larry, your comments about computer shogi vs. chess surprises me. In 1985 or >86, you stopped by Seattle (the Last Exit) while I was living there. I asked >you about this very question at that time, because it was my opinion that >shogi would be harder to program. Your answer then was that shogi should be >easier to program. Did I misunderstand you originally, or did you change >your mind in the intervening years? I cannot imagine having said that. I did have the opinion that Shang-Chi (Chinese Chess) might be easier to program than Western Chess; so perhaps I was referring to that game. >You also said then, as you do now, that >Go would be hardest of all. Ironically, I've never been convinced of that. > I think it just requires a very different approach than the standard >chess/shogi programming methods. > One of the speculations that people like to discuss is whether the success >of computer chess could kill the popularity of chess for humans (or, at >least, for professionals). If shogi and go are harder to program, then we >can imagine a day when chess is mostly relegated to casual games for kids, >while serious players play only shogi & go. The history of checkers is a >good precedent for this. Of course, if a computer conquers shogi & go as >well, then we would need to invent a new game with a geater branching level >(say, > 1000). I don't think the branching factor is the main issue. The key point is the difficulty of evaluating positions. In checkers, winning material is everything. In chess, it is dominant, and most other positional factors can be evaluated by simple rules and summed. In shogi, material is still very important, but the relative importance of position vs. material varies greatly thruout the game in ways that are very hard to express in clear, programmable rules. In Go, even to count who is ahead in "material" (i.e. points) is very difficult, as it's often very unclear which groups are alive and which are not. This is why, I believe, that the best pc checker program is near Championship level, the best chess program at Grandmaster level, the best Shogi program at 1 Dan level, and the best Go program at perhaps 7-10 kyu level. The branching factor is a minor consideration, since a larger branching factor makes the game more difficult for both human and computer, and also because the computer partially compensates by using the Alpha-Beta algorithm. I do agree that the success of computers (and Deep Blue's victory in particular) in chess should tend to increase the popularity of shogi vs. chess, especially since shogi programs are now good enough to be sparring partners for the average player without being a threat to professionals for the foreseeable future. I think that whoever wishes to convert chess players to shogi should point to the superiority of humans over computers in shogi as evidence that shogi is more of a creative, imaginitive game than chess, which is more of a logical exercise. > Incidentally, drops are not the only reason shogi is harder to program than >chess. There are fewer long-range pieces and and slightly larger board. > This means that there are a greater number of variations to reach any given >position, and that it will be harder to filter out these variations for >selective searches. Actually, if there are in fact more ways to reach a given position in shogi, that should make it easier for the computer because of Hash Tables, which deal well with transpositions. Also I think selective search will work better in Shogi than in chess, precisely because there are more silly moves to prune out. Despite these points, the evaluation issue is the reason I consider Habu safe from computers for at least twenty years. > >Ben Bednarz, Salem, OR > > Larry Kaufman, 301-309-0904, 9213 Wooden Bridge Road, Potomac, Md. 20854