One Rook or Two

White to move

According to Bogdan Lalic  (Chess Informant 113/141), his 21.b3 in this position was an error. He offered as an alternative:

21.Qxc5 Rxc5 22.Rac1 Rxc1 23.Rxc1 g6 24.g3 Rb4 25.b3! Rxb3 26.Rc5 Ra3 27.Rxa5 when it should be clear that White retains winning chances.

Black to move

Theoretical Position

In the game, after 21.b3, the queens were exchanged and White managed to retain the a-pawn and a one pawn advantage long enough to advance the pawn to a7. However, with each player possessing two rooks, Black stopped the pawn on a7, hitting it with two rooks. Only one rook defended it.

The players agreed to a draw.

Black to move

Final Position