Congrats! :) BTW, instead of max(min()) when I wrote mine I used this equality: V'(s) = 1 - V(swap_players(s)), where swap_players(s) switches X and O pieces.

Congrats! :) BTW, instead of max(min()) when I wrote mine I used this equality: V'(s) = 1 - V(swap_players(s)), where swap_players(s) switches X and O pieces. And I only need to do max(). Don't know if that would make your program simpler.