Author: Tord Romstad
Date: 09:40:39 05/25/05
Go up one level in this thread
On May 25, 2005 at 11:51:31, Paul Clarke wrote: >On May 25, 2005 at 06:17:02, Tord Romstad wrote: > >>On May 25, 2005 at 05:56:22, Vasik Rajlich wrote: >>> >>>So maybe you could say that if you want to be an engineer, write a chess >>>engine, while if you want to be an innovator, write a go engine. >> >>That's indeed an excellent summary. I would like to add that if you want >>to combine both types of skills, shogi is somewhere in the middle (though >>of course much closer to chess). > >Shogi does indeed look interesting. I've written a toy shogi program using >alpha-beta search with the usual refinements; it plays fairly badly, >particularly when there are a few pieces available to drop and the branching >factor jumps to 200 or more. Actually, I don't think the big branching factor is the most important difficulty in shogi (or in go) compared to chess. The really big problem is that it is so much harder to write an accurate evaluation function. Chess positions are relatively easy to evaluate because material (which is easy to count) is usually more important than everything else. Shogi is different. Except in the early phases of the game, material is less important than factors like initiative and king safety, which are very difficult to quantify. I am the author of an engine for a chess-like game with a relatively big branching factor: Glinski's hexagonal chess. The branching factor is not quite as high as in Shogi, but positions with more than 100 legal moves are very common. I initially expected it to be considerably more difficult to make a strong program for this game than for normal chess, but this does not seem to be the case. My hexagonal chess engine is very similar to my normal chess engine (in fact, most of the code is shared), and the same techniques seem to work equally well in both games. It is difficult to estimate the strength of the hexagonal chess engine accurately, but my impression is that it is roughly comparable to my normal chess engine. >It could be improved quite a lot without abandoning >alpha-beta: the evaluation function is cobbled together from my limited shogi >knowledge, and I've payed very little attention to performance. However, I'm >tempted to switch to something similar to B*, mainly because it looks like an >interesting thing to play with. B* certainly looks fun, and I hope to try it out myself some day. I doubt that it is the easiest way to go to create a strong shogi program, though. >There's an interesting description of the 1997 computer shogi champion YSS at >http://www32.ocn.ne.jp/~yss/book_e.html (the level of detail is similar to Ed >Schroeder's pages on Rebel). Thanks for the link! Looks really interesting. Tord
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.