Bartel, Mateusz – Chatalbashev, Boris

2634 2010 · Draw

Pirc Defense, 2010: Mateusz Bartel (2634) against Boris Chatalbashev (2555). White castles queenside and the game stays balanced for a long stretch, until 35...f4 swings the evaluation from +0.9 to +2.5 and hands White a clear edge. The pendulum swings back, and at the critical point 38.Ka2 lets the chance slip: from -2.6 to -0.5. Repeated queen checks then settle the game as a draw. Accuracy: 86% for White, 82% for Black. Two lessons: one careless pawn push can cost a pawn and a half of evaluation, and a king move played without necessity can give back everything you just won.