Explanation
Open the explanation (shows the answer)
The answer is b8. With best play to the end: +4 (a win by 4).
Best line: b8 d7 e6 h7 d8 f7 f8 g8 e7 e8
Other moves
| Move | Result | Why |
|---|---|---|
| d8 | -16 (a loss by 16) | Opponent's moves: 8 after this move, 6 after b8. The opponent's best answer is e8 (then d7 e7 f7). |
| d7 | -18 (a loss by 18) | The opponent's best answer is h7 (then e6 d8 e7). |
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.