Oleksandr Bortnyk: 31...Nd5? (blitz, 2026-08-28)

Deep puzzles: what the analysis missed

8 moves

Oleksandr Bortnyk to move, Black. Lichess's analysis gave the move played no mark (-1.05 before, -0.85 after). A 20-million-node search calls it a mistake, 13 win-chance points against a best move that is unique. Find it before opening the sideline.

The game move. Lichess: -1.05 to -0.85, no label. At 20M nodes: blunder, 17.7 win% given up, 13 points worse than Qb6.