Comment by lxgr
1 year ago
> good chess isn't played as a series of independent moves -- it's played as a series of moves connected to a player's strategy.
Maybe good chess, but not perfect chess. That would by definition be game-theoretically optimal, which in turn implies having to maintain no state other than your position in a large but precomputable game tree.
Right, but your position also includes whether or not you still have the right to castle on either side, whether each pawn has the right to capture en passant or not, the number of moves since the last pawn move or capture (for tracking the 50 move rule), and whether or not the current position has ever appeared on the board once or twice prior (so you can claim a draw by threefold repetition).
So in practice, your position actually includes the log of all moves to that point. That’s a lot more state than just what you can see on the board.