Sergei Zhigalko: 15...Bg6? (blitz, 2026-07-14)

Deep puzzles: what the analysis missed

8 moves

Sergei Zhigalko to move, Black. Lichess's analysis gave the move played no mark (-0.89 before, -0.62 after). A 20-million-node search calls it a mistake, 10 win-chance points against a best move that is unique. Find it before opening the sideline.

The game move. Lichess: -0.89 to -0.62, no label. At 20M nodes: mistake, 10.3 win% given up, 10 points worse than Nc2.