Explanation
Open the explanation (shows the answer)
The answer is f2. With best play to the end: +4 (a win by 4).
Best line: f2 h7 h3 f1 g1 h1 g2 h2 e1 d1
Other moves
| Move | Result | Why |
|---|---|---|
| e1 | -4 (a loss by 4) | Openness: 3 for this move (flips 5), 1 for f2 (flips 3). The opponent's best answer is f1 (then d1 f2 g2). |
| f1 | -8 (a loss by 8) | Openness: 3 for this move (flips 2), 1 for f2 (flips 3). The opponent's best answer is f2 (then h3 h7 g1). |
| g2 | -8 (a loss by 8) | g2 is an X-square (diagonal to the corner h1). While the corner is empty it tends to give the corner away. After this move the opponent can play the corner h1. Openness: 3 for this move (flips 2), 1 for f2 (flips 3). The opponent's best answer is h1 (then e1 d1 f1). |
| d1 | -12 (a loss by 12) | Openness: 4 for this move (flips 7), 1 for f2 (flips 3). The opponent's best answer is e1 (then g2 f2 f1). |
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.