Explanation
Open the explanation (shows the answer)
The answer is g8. With best play to the end: +4 (a win by 4).
Best line: g8 c2 c1 b1 a1 b2 a3 f8 e8 a2
Other moves
| Move | Result | Why |
|---|---|---|
| c2 | -6 (a loss by 6) | Opponent's moves: 6 after this move, 4 after g8. The opponent's best answer is g8 (then a3 c1 f8). |
| a2 | -10 (a loss by 10) | Opponent's moves: 7 after this move, 4 after g8. Openness: 3 for this move (flips 1), 1 for g8 (flips 1). The opponent's best answer is a3 (then g8 c1 c2). |
| a3 | -10 (a loss by 10) | Opponent's moves: 7 after this move, 4 after g8. Openness: 3 for this move (flips 9), 1 for g8 (flips 1). The opponent's best answer is g8 (then e8 c1 c2). |
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.