Backgammon vs the computer
No friend around? The computer is always ready to play. Choose a level, play, and after the game get an analysis of every move.
Four levels
| Level | How it plays | Error rate (PR) |
|---|---|---|
| Easy | Plays reasonably and misses quite a bit | about 17 |
| Medium | A good café player, makes the occasional mistake | about 10 |
| Strong | Almost always picks the best move | about 4 |
| Champion | Also checks all 21 of your possible rolls before choosing. Very hard to beat | about 1 |
PR is the standard error rate in the backgammon world: how much you lose on average per decision, times 500. The lower the number, the better the play. World-class players get 2 to 5.
The computer's dice
The computer gets random dice exactly like yours, at every level. The level only changes its decisions, never the rolls, and it doesn't know in advance what will come up. More on this: Our dice are fair.
How it thinks
The computer uses a neural network we trained ourselves: first on hundreds of thousands of games against itself, then on millions of positions scored by GNU Backgammon, the strong free backgammon program. At the end of the game, in bearing off, it uses exact tables.
Learn as you play
- Hint: the three best moves, with arrows on the board.
- The coach: stops you before a blunder and shows you the options.
- Odds meter: each side's chance of winning, at every moment.
- Post-game analysis: the big mistakes, luck and PR, with a replay of every move.
A game where you used a hint or the coach is marked "with help" and isn't rated.