12-01-2019, 11:23 AM
In the case of Chess, we have added values for the different piece types to the metadata, and this is used for a simple material score in the heuristic evaluation function. So, for now, this is a very simple little bit of domain knowledge that we have specifically added to Chess.
For all other games, currently, we automatically construct a heuristic evaluation function with a material component and a mobility component.
- The material component gets a weight of 1.0, and simply sums up the pieces owned by a player to determine the score for that player (ignoring differences in piece types).
- The mobility component gets a weight of 0.01 (so it typically only ends up functioning as a tie-breaker in games where material is also relevant). Its score is the number of legal moves for the current player to move in a state, and 0 for every other player.
Because I'm personally not looking forward to manually adding domain knowledge in the form of heuristic evaluation functions to all the.... 160-180ish games we currently have, we're instead looking to automatically learn them automatically from self-play. Basic, learned heuristics for all games will hopefully be included in the first full v1.0.0 Ludii release in January.
For all other games, currently, we automatically construct a heuristic evaluation function with a material component and a mobility component.
- The material component gets a weight of 1.0, and simply sums up the pieces owned by a player to determine the score for that player (ignoring differences in piece types).
- The mobility component gets a weight of 0.01 (so it typically only ends up functioning as a tie-breaker in games where material is also relevant). Its score is the number of legal moves for the current player to move in a state, and 0 for every other player.
Because I'm personally not looking forward to manually adding domain knowledge in the form of heuristic evaluation functions to all the.... 160-180ish games we currently have, we're instead looking to automatically learn them automatically from self-play. Basic, learned heuristics for all games will hopefully be included in the first full v1.0.0 Ludii release in January.