How to play an opening 4-2
Play 8/4 6/4. It is 0.112 ahead of the next best play, 24/22 13/9. With it you win 53.8% of games, 17.1% of all games by a gammon.
The arrows show 8/4 6/4. The position is the start of the game with your checkers at the bottom and 4-2 to play, which is the roll that decided who goes first, so no doubles.
Open it in Study to try every play against the engine and see how your opponent's replies change the picture.
Every play the rollout compared
| Play | Equity | Behind | Wins | Gammons won | Gammons lost |
|---|---|---|---|---|---|
| 8/4 6/4 | +0.123 ± 0.002 | 53.8% | 17.1% | 12.6% | |
| 24/22 13/9 | +0.011 ± 0.002 | 0.112 | 50.1% | 14.5% | 13.7% |
| 13/11 13/9 | +0.010 ± 0.002 | 0.114 | 49.9% | 15.4% | 14.3% |
How these numbers were made
Every play within reach of the best was played out 2592 times, each game to its end, by Colossus, the strongest HedgeHog network on the engine benchmarks, choosing every later move at 1-ply. The two rolls after the play cycle evenly through all 36 outcomes each, which takes most of their luck out of the comparison.
Equity is what the play is worth per game in a money game without the cube, from the side of the player who rolled: +1 is a certain single win, and a gammon counts twice. The figure after ± is one standard error. Two plays closer than twice the error of their difference are a tie, and this page calls them one.
In a match, the score can change the right play, above all near the end, where a gammon may be worth nothing or everything; the match equity table is where that starts. To see how your own opening plays compare, analyse a match.