4 ms·
Check out this chess programming wiki article [1] for a (still fairly hand-wavy) rationale for similar piece values, and the Wikipedia article on chess piece re
by kamkha 10y ago
Check out this chess programming wiki article [1] for a (still fairly hand-wavy) rationale for similar piece values, and the Wikipedia article on chess piece relative values [2] for a more in-depth look at various weightings. Some modern approaches use analysis of a huge corpus of master games to come up with piece values, but many of the systems are based on intuition and empirical evidence.
[1] https://chessprogramming.wikispaces.com/Simplified+evaluation+function https://chessprogramming.wikispaces.com/Simplified+evaluatio...
[2] https://en.wikipedia.org/wiki/Chess_piece_relative_value https://en.wikipedia.org/wiki/Chess_piece_relative_value
- socmag 10y agoGood parent question and interesting links, thanks, will take a look. To follow on though, shoukdn't it technically be the case that piece values should in theory fluctuate based on current situation. For instance, my castle is worth zero to me if I'm throwing it so I can get you in check. Will I know modern chess engines take this stuff into account. Mostly just a random thought.
- jedimastert 10y ago> values should in theory fluctuate based on current situation The author touched this a little bit with adding the position adjustments > my castle is worth zero to me if I'm throwing it so I can get you in check. I know what you mean, but castling into or through check isn't a legal move and shouldn't show up in your list of possible moves.
- socmag 10y agoRight, although I didn't mean castling into check. I meant tempting a greedy algorithm by throwing away a high value piece (which was always a weakness of early chess machines), although I realize the tree search would spot that. Also now that I'm awake, read the article fully now. Very cool, makes me want to try building one!
- earthtolazlo 10y ago> To follow on though, shoukdn't it technically be the case that piece values should in theory fluctuate based on current situation. Yes. One common example is knights and bishops. Both are worth about 3 pawns, but knights are generally more useful in closed positions due to their ability to jump over pieces, while bishops are better in open positions since they can more attack and move long distances.
- socmag 10y agoFascinating. So in some sense, and I'm just brain-farting here, the value of a piece is a weighted sum of all the possible squares it could occupy during move generation. Something like a rudimentary path trace. Now trying my best not to get distracted building chess machines. :/
- socmag 10y agoGood parent question and interesting links, thanks, will take a look. To follow on though, shoukdn't it technically be the case that piece values should in theory fluctuate based on current situation. For instance, my castle is worth zero to me if I'm throwing it so I can get you in check. Will I know modern chess engines take this stuff into account. Mostly just a random thought.