O'Dea, David – Harikrishna, Penteala

2474 2004 · Checkmate — Black wins

An Alekhine Defense on the label, an open fight on the board: O’Dea (2474) against Harikrishna (2570) in 2004. White builds a clear advantage and holds it for many moves, but never finds the strongest continuation. Move 18 is the marker: 18.Ra4 is a missed chance, the evaluation sliding from +2.0 to +4.7. Black’s reply 18...f5 is itself a mistake, from -4.7 to -3.2, yet 20.Ng5 (+2.8 to +4.8), 26.Bf6 (+5.6 to +9.6) and 27.Ke2 (+8.6 to +13.0) let a winning position drain away. With 75% good-or-better moves against 97%, the bill arrives: 32...Qc1#. A big edge still has to be converted.