Ivanchuk Missed 23.a6 !

According to the analysis in the official site, Ivanchuk missed a great chance on move 23 in his game against the last seed - GM Jan Smeets. The best move 23.a6! could turn the game into his favour. As we already know, Ivanchuk lost the game on time. Below are the critical position.

Ivanchuk,V (2779) - Smeets,J (2601) [D44]

Corus A Wijk aan Zee NED (1), 17.01.2009

White to play

In the actual game, Ivanchuk play 23.Rb1 However, he should have play the stronger 23.a6! b6 (23...Nc6? 24.axb7 Rb8 25.Ba6 with a large advantage ) 24.Bxb6 axb6 25.dxe5
...and white passed pawn on a - file could be decisive and difficult to handle !