AlphaFour is a Connect Four AI built with Python and Pytorch, that selects moves using a nerual network and a Monte Carlo search tree similar to DeepMind's AlphaGo and AlphaZero. Connect is a solved game, so this might be too easy for a computer, but it's a way to get my feet wet before trying chess.

To play a game, simply run:

python play_game.py [-p1 <agent1>] [-p2 <agent2>]

-p1 and -p2 allow you to specify the Agent used for player one and/or player two respectively, with player one making the first move. The following player types are available:

• AlphaBeta: Basic algorithm that uses alpha-beta pruning to choose the next move.
• Human: Rather than automatically suggesting moves, the agent will prompt the user for the next move. Allows you to play against the AI, or with a friend if you really want to play connect4 and can't be bothered to go out and buy a board.

By default, play_game.py will start a game with a Human as player one, and AlphaBeta as player two. You can specify either player to override the default behaviour. Examples:

python play_game.py                          // Default behaviour. Human vs. AlphaBeta
python play_game.py -p1 AlphaBeta            // AlphaBeta vs. AlphaBeta
python play_game.py -p1 AlphaBeta -p2 Human  // Give robot first move