In game 5 of the 2013 World Chess Championship match, Carlsen had captured a bishop with 20.cxb6, and Anand maintained material balance by capturing a knight with 20...fxe4, also attacking White's bishop (see diagram). Instead of immediately taking the pawn with 21.Bxe4, which would have given Anand the opportunity to fix his queenside pawn weaknesses with 21...axb6, Carlsen played the zwischenzug