Yeah thats exactly it. The rules are easy enough to put into the form of matching strings. I gave an explicit example further down in the thread. At no point is

Yeah thats exactly it. The rules are easy enough to put into the form of matching strings. I gave an explicit example further down in the thread. At no point is it required to even convert the game history into a board state data structure. The game history in standard notation itself is sufficient as a game state. To know where a piece is, simply iterate back from the end until finding the last mention of it then iterate forward to make sure it wasn't captured.