As an educational experience I implemented a limited ply minimax game of Connect 4. I tried adding in alpha-beta pruning. It seems pretty simple and I don''t see how I made a mistake, but it seems to me that I must have. It plays differantly. Without changing the number of plys a correctly implemented alpha-beta pruning should result in the exact same choice in moves by the computer, right? Another question was about valuing the board at the ply limit. The method I use is to value each of the 54 ways you could get a "Connect 4" on a 6x6 board. If an opponents piece is in a line then the value is zero. Otherwise it is the number of your own pieces plus one. The value of the board is then the differance of its value for the computer and human. The computer plays fine so I don''t need a better way. Rather I''m wondering how else could you value the board? Finally where do I go from here? Obviously getting the alpha-beta pruning working is one thing to do, but what is a step up?