Explanation
Open the explanation (shows the answer)
The answer is b2. With best play to the end: +4 (a win by 4).
Best line: b2 g2 h1 g1 h2 g3 a1 f8 f7 g8
Other moves
| Move | Result | Why |
|---|---|---|
| g3 | -4 (a loss by 4) | The opponent's best answer is h2 (then a1 b2 h1). |
| a1 | -10 (a loss by 10) | The opponent's best answer is b2 (then g3 f8 f7). |
| h2 | -16 (a loss by 16) | Openness: 2 for this move (flips 1), 0 for b2 (flips 3). The opponent's best answer is g3 (then a1 f8 g1). |
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.