By Eric Morrow
In the Woman’s World Chess Championship, which is taking place Sept. 10-28, Hou Yifan of China has a commanding lead over Woman’s World Champion Anna Ushenina of Ukraine. Hou will likely regain the title she lost to Ushenina last year.
This week’s position is based on the third game of their match. Hou is black; Ushenina, white. Hou throws a one-two punch with her knights to exploit Ushenina’s vulnerable back rank. With this hint in mind, please try to find how black forces mate in four moves.
Black first checks white from e2 with its c3 knight. This forces the white king into the corner on h1. Black next uncorks the e4 knight, moving it to take f2. This checks the white king and leaves him without any flight squares.
White’s rook is therefore forced to accept the knight sacrifice on f2 and take the knight. Black’s queen then checks white from the back rank on either d1 or b1.
White can only defer mate by blocking the queen’s assault with its rook. Black’s queen then gobbles up white’s rook and mates white.
Among all active players, Hou is ranked No. 193 in the world and Ushenina is No. 792. It is thus no surprise that Hou will likely regain her title.
However, world rankings can be deceptive. Hou placed ahead of many players with much higher rankings at one of the world’s most prestigious chess tournaments in January.