Othello You may win.

Microsoft's Reversi and Rixstep's Othello were written at about the same time and are similar in their internal design, but differences do exist which normally result in a victory for Othello.

Reversi only offers one type of play, Othello offers two. Reversi offers only four ply levels (1, 2, 4, 6) whilst Othello offers all sixty-one. In addition, Othello adds crunching which kicks in towards the end of the game.

Mate in Ten

(In the game above, pictured on the left, Othello has just finished calculating its next move, ten from the end, and has issued the dire news 'You will lose'. The image on the right shows how the came ended. It's brutal.)

The Power of Crunching

Strategy is one thing but crunching's another. Why Microsoft chose to simply change strategy during the end game is a mystery, but they get roundly trounced for it.

Here's some fun. Set the ply level very low but the crunch level very high and see what happens.

1. Othello seems lost with only 15 pieces on the board.



2. But Othello declares otherwise.



3. The final board.



4. Othello wins.

Ply Theory

Both games use minimax ply theory with alpha-beta pruning but Othello goes a bit further. Othello plays an authentically random game whereas Reversi does not, uses two strategy boards where Reversi uses only one, and abandons its strategy boards ('crunching') during the end game where Reversi rewrites its strategy board instead. Reversi can never know the outcome of a game, but Othello, calculating all remaining moves, can tell you convincingly 'you will lose'.