Explanation
Open the explanation (shows the answer)
The answer is e1. With best play to the end: +2 (a win by 2).
Best line: e1 e8 c1 a1 a2 c8 d7 b7 a8 c7
Other moves
| Move | Result | Why |
|---|---|---|
| f8 | -2 (a loss by 2) | The opponent's best answer is b7 (then e1 g8 e8). |
| e8 | -4 (a loss by 4) | The opponent's best answer is c7 (then e1 g8 c1). |
| c1 | -8 (a loss by 8) | The opponent's best answer is e1 (then f8 e8 g8). |
| g8 | -8 (a loss by 8) | The opponent's best answer is e8 (then f8 d7 e1). |
| g1 | -22 (a loss by 22) | The opponent's best answer is e1 (then f8 c1 g8). |
About these puzzles
Each position comes from a real game. The engine solved it to the end (perfect play by both sides) and only positions with a single best move, clearly better than the second-best move, were kept. "Best play wins by N" is the final disc margin when both sides play perfectly.
If you play a different move, you see the final margin your move leads to with perfect play afterwards, and how much it gave up. Results are stored only in this browser.
To be graded during a full game, go to the Reversi dojo.