4 ms·

If I understand your code correctly in analyse_evaluations, you're defining a "surprising move" as a move that has a large change in valuation when it's conside

If I understand your code correctly in analyse_evaluations, you're defining a "surprising move" as a move that has a large change in valuation when it's considered at a higher depth. So if a "human" (really Stockfish at depth 5) evaluates a move as +1 and a "computer" (Stockfish now at depth 11) evaluates the move as +5, the move is surprising. This is pretty interesting, but I'm not sure if it fully captures all the nuances of what a surprising move is. You might be able to classify a move as tactically surprising if it becomes clear after depth 7 that the ending position is favorable. However, in my opinion truly surprising moves are ones that carry plans that I haven't even considered. Hence, this methodology doesn't capture moves that are positionally surprising as there wouldn't be such a drastic change in evaluation at different depths. I'm not sure where you would start to figure that one out though :) That being said this is really cool work!

te_platt 10y ago
Surprising may be a bit subjective. I know that I am all too often surprised by my opponent - and not in a good way. This may be a good way to study what kind of patterns have interesting weaknesses.
- twothamendment 10y ago
  Surprising is very subjective. I was playing chess in a cabin full of people and found the checkers game next to me to be more entertaining - most likely because of the people. My chess moves were not quite random, but because I wasn't really paying attention they were really frustrating my opponent because he couldn't make sense of what I was doing. My moves were either not very logical or so brilliant that he didn't know what I was up to and it was really getting into his head. Surprising moves? Yes. Good moves? Not so much.
yakult 10y ago
You can filter for this: Take a database of games from pro players; Take the set of all moves where Stockfish-5 agrees that the move actually played is the optimum. Filter for all the moves where Stockfish-11 has a different opinion that results in a big gain in position. What you get is a list of moves that would surprise pro-players under time pressure. I wouldn't be surprised if professional chess players are all running a version of this against individual known opponents before a tournament to probe for weaknesses. A harder problem would be to cross-reference this final list with the post-game opinions published by professional commentators and identify major discrepancies. This would be the "wouldn't have thought of it in a million years" list.
- Matetricks 10y ago
  The list that's returned still contains mainly tactical surprises where Stockfish inaccurately evaluated the position at the end of depth 5. I think what I'm trying to say is there are some moves in a position that aren't tactically surprising (a piece sacrifice, a crazy attacking move, etc.) but positionally surprising (a long maneuver to get a piece to a certain square that I didn't think of). These positionally surprising moves aren't captured by this methodology because they don't involve large fluctuations in valuation when the depth changes. As to your second point, an issue with how computer chess affects the modern scene is how playing the "best" move in any given position isn't representative of how humans play. Humans carry out plans and evaluate positions to the best of their ability, but the heuristics and procedure they use aren't the same as a computer's. For example, Karjakin didn't prepare for his match against Carlsen last month by playing a bunch of games against Stockfish. Rather he probably analyzed Carlsen's past games and opening choices to come up with a strategy. I do think you can come up with a way to prepare against individually known opponents by identifying weaknesses programmatically. You can model a human's approach to playing chess as a distribution of parameters (material, king safety, pawn structure, etc.) that take in the current position and return the best move. You also have Stockfish's evaluation which returns the "best" move. With this, it's possible that you could use build a neural network that learns to play very similarly to a certain player by using their past games as a training set and comparing the chosen move to Stockfish's move. The network could learn to mimic the heuristics that the human individual uses to make decisions and playing against this new AI would be great practice for preparing against specific opponents.
  - yakult 10y ago
    I'm not sure I follow your point about tactical vs positional surprise. Surely the ultimate goal of the positional surprise is the same as the tactical surprise - you get an advantage at the end of an expected series of moves. Otherwise what's the point of getting into a surprising position that's not better than the conventional one? My question is, is there any difference here that can't be solved by, say, upping the ply-number? On humanlike chess-AI: have an adversarial network that works to classify human vs machine players, and optimize for humanness * strength-of-play in the AI?
zwischenzug 10y ago
This is pretty much what I wanted to say. What is a surprising move varies greatly from player to machine. Here's a good example: http://www.chessgames.com/perl/chessgame?gid=1064780 http://www.chessgames.com/perl/chessgame?gid=1064780 Capa's move 10 here (Bd7) is completely surprising to the vast majority of players and computers. It breaks most of the standard 'rules' of development and space control. However, it doesn't move the needle in terms of tactical significance at all. To me, that's a surprising move.

te_platt 10y ago

Surprising may be a bit subjective. I know that I am all too often surprised by my opponent - and not in a good way. This may be a good way to study what kind of patterns have interesting weaknesses.

twothamendment 10y ago
Surprising is very subjective. I was playing chess in a cabin full of people and found the checkers game next to me to be more entertaining - most likely because of the people. My chess moves were not quite random, but because I wasn't really paying attention they were really frustrating my opponent because he couldn't make sense of what I was doing. My moves were either not very logical or so brilliant that he didn't know what I was up to and it was really getting into his head. Surprising moves? Yes. Good moves? Not so much.

yakult 10y ago

You can filter for this: Take a database of games from pro players; Take the set of all moves where Stockfish-5 agrees that the move actually played is the optimum. Filter for all the moves where Stockfish-11 has a different opinion that results in a big gain in position. What you get is a list of moves that would surprise pro-players under time pressure. I wouldn't be surprised if professional chess players are all running a version of this against individual known opponents before a tournament to probe for weaknesses. A harder problem would be to cross-reference this final list with the post-game opinions published by professional commentators and identify major discrepancies. This would be the "wouldn't have thought of it in a million years" list.

Matetricks 10y ago
The list that's returned still contains mainly tactical surprises where Stockfish inaccurately evaluated the position at the end of depth 5. I think what I'm trying to say is there are some moves in a position that aren't tactically surprising (a piece sacrifice, a crazy attacking move, etc.) but positionally surprising (a long maneuver to get a piece to a certain square that I didn't think of). These positionally surprising moves aren't captured by this methodology because they don't involve large fluctuations in valuation when the depth changes. As to your second point, an issue with how computer chess affects the modern scene is how playing the "best" move in any given position isn't representative of how humans play. Humans carry out plans and evaluate positions to the best of their ability, but the heuristics and procedure they use aren't the same as a computer's. For example, Karjakin didn't prepare for his match against Carlsen last month by playing a bunch of games against Stockfish. Rather he probably analyzed Carlsen's past games and opening choices to come up with a strategy. I do think you can come up with a way to prepare against individually known opponents by identifying weaknesses programmatically. You can model a human's approach to playing chess as a distribution of parameters (material, king safety, pawn structure, etc.) that take in the current position and return the best move. You also have Stockfish's evaluation which returns the "best" move. With this, it's possible that you could use build a neural network that learns to play very similarly to a certain player by using their past games as a training set and comparing the chosen move to Stockfish's move. The network could learn to mimic the heuristics that the human individual uses to make decisions and playing against this new AI would be great practice for preparing against specific opponents.
- yakult 10y ago
  I'm not sure I follow your point about tactical vs positional surprise. Surely the ultimate goal of the positional surprise is the same as the tactical surprise - you get an advantage at the end of an expected series of moves. Otherwise what's the point of getting into a surprising position that's not better than the conventional one? My question is, is there any difference here that can't be solved by, say, upping the ply-number? On humanlike chess-AI: have an adversarial network that works to classify human vs machine players, and optimize for humanness * strength-of-play in the AI?

zwischenzug 10y ago

This is pretty much what I wanted to say. What is a surprising move varies greatly from player to machine. Here's a good example: http://www.chessgames.com/perl/chessgame?gid=1064780 http://www.chessgames.com/perl/chessgame?gid=1064780 Capa's move 10 here (Bd7) is completely surprising to the vast majority of players and computers. It breaks most of the standard 'rules' of development and space control. However, it doesn't move the needle in terms of tactical significance at all. To me, that's a surprising move.