81–90 of 113 posts
I always thought of the heuristics for evaluating a chess position as the really hard part of building a chess engine; i.e. how do you capture all of the positional subtleties in a number to feed into minimax? But looking at the source, it's not really that complicated [1]. Can someone who knows more than me comment on that? Is it that the innovations are elsewhere? That good chess really can be boiled down to [1] ht…
Can anyone comment on what makes stockfish different from other chess engines? If I'm curious about state of the art in computer chess, is it worthwhile to study its source? What interesting ideas should I expect to see there beyond what I vaguely know to be the standard approach from introductory AI courses, i.e. some sort of alpha-beta pruning search?
You should indeed study Stockfish's source, not because it is the strongest computer chess engine, but because it is exceedingly well-written. Most engines that are public are a big hacky mess, but the Stockfish maintainers have made cleanliness a really high priority (sometimes proposed changes that increase the engine's strength are rejected because they're too much code), and it has clearly paid off.
that seems insane.
What I would love to see is work on chess engines having better strength levels for amateurs. For me at least there is a line where everything below a certain level I can beat 95 percent of the time and everything at or above that level I lose to 95 percent of the time.
Has anyone else watched http://en.lichess.org/tv ? If this is two humans playing against each other in real-time, that is really impressive! It's so mind-boggling fast (mind you I'm not a chess player).
Earlier quoted context omitted.
You should indeed study Stockfish's source, not because it is the strongest computer chess engine, but because it is exceedingly well-written. Most engines that are public are a big hacky mess, but the Stockfish maintainers have made cleanliness a really high priority (sometimes proposed changes that increase the engine's strength are rejected because they're too much code), and it has clearly paid off.
>sometimes proposed changes that increase the engine's strength are rejected because they're too much code that seems insane.
On my first try I managed to draw the highest AI level, rated at 2510, while my rating is under 2000 irl. (I was unable to find an "offer draw" button so relied on the 50-move rule) Against stockfish running on my PC that would be impossible. http://en.lichess.org/reDfuSvI
Can anyone comment on what makes stockfish different from other chess engines? If I'm curious about state of the art in computer chess, is it worthwhile to study its source? What interesting ideas should I expect to see there beyond what I vaguely know to be the standard approach from introductory AI courses, i.e. some sort of alpha-beta pruning search?
You should indeed study Stockfish's source, not because it is the strongest computer chess engine, but because it is exceedingly well-written. Most engines that are public are a big hacky mess, but the Stockfish maintainers have made cleanliness a really high priority (sometimes proposed changes that increase the engine's strength are rejected because they're too much code), and it has clearly paid off.
I always thought of the heuristics for evaluating a chess position as the really hard part of building a chess engine; i.e. how do you capture all of the positional subtleties in a number to feed into minimax? But looking at the source, it's not really that complicated [1]. Can someone who knows more than me comment on that? Is it that the innovations are elsewhere? That good chess really can be boiled down to [1] ht…
Nearly all the evaluation terms in Stockfish have been extensively tuned. Joona Kiiski used the SPSA[1] algorithm on a lot of them. Others have been hand-tuned using tens of thousands of games per attempt on fishtest [2]. Fishtest actually just recently got support for running SPSA tuning as well. There is also a strong bias towards simplification, so if an evaluation feature is not proven to be an improvement it wil…
Earlier quoted context omitted.
You should indeed study Stockfish's source, not because it is the strongest computer chess engine, but because it is exceedingly well-written. Most engines that are public are a big hacky mess, but the Stockfish maintainers have made cleanliness a really high priority (sometimes proposed changes that increase the engine's strength are rejected because they're too much code), and it has clearly paid off.
>sometimes proposed changes that increase the engine's strength are rejected because they're too much code that seems insane.