Oleksandr Bortnyk: 54...Qf6? (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 (-1.58 before, -1.03 after). A 20-million-node search calls it a blunder, 20 win-chance points against a best move that is unique. Find it before opening the sideline.

The game move. Lichess: -1.58 to -1.03, no label. At 20M nodes: blunder, 17.5 win% given up, 20 points worse than Qa7+.