Stripunsky, Alexander – Christiansen, Larry Mark

2556 2009 · Black wins (resignation, time or agreement)

Philidor Defence, 2009: Stripunsky (2556) against Christiansen (2578), a closed middlegame where White manoeuvres patiently on the queenside (10.a4, 21.b3) while Black regroups around the e-file. Both sides played cleanly — 90% accuracy for White, 94% for Black. The first swing comes on move 38: 38...Nf6 shifts the evaluation from 0.0 to +2.5, letting the balance slip. The pendulum then swings back, and with White at −3.6, 63.Qa8+ misses the turn to +6.0; 63...Nxa8 ends it, 0-1. The takeaway: in slow manoeuvring positions, one overlooked chance can erase dozens of accurate moves.