© 2015 Jonathan David Whitcomb

Benefits From Chess Spending a reasonable amount of time in chess can improve your concentration in other subjects. In addition, playing chess with another person can be a positive social experience, far better than spending time alone in front of a television screen.

Diagram-1: White to move and win

In Diagram-1, White may have more than one way to win this queen-versus-rook end game. Let’s look at one method: Qe4+ forces the black king to a2, for moving to a1 or b2 will allow the queen to win the rook with Qd4+ (putting the black king on a1 would not save the rook, for after Qd4+ and Rb2+, the white king would move to c1, winning the pinned rook, not to mention checkmate soon with Qxb2#). In Diagram-2, we can see why White chose e4 for the queen to check the defending king: Notice that the white king may now advance on the black king, for the queen covers c6, preventing a rook check there. This illustrates a technique that is sometimes available to the attacker. It’s when the rook is greaty separated from the defending king in this queen-versus-rook end game: The queen can sometimes prevent a rook-check, before or after the attacking king advances on the defending king. The first thing to watch for, when you’re the fortunate chess player with the queen in this kind of end game, is if a checking maneuver by the queen can eventually force a forking of the rook. This is not always available, so you need alternatives. The combination shown in these few diagrams is not easily forseen over the board, even by a grandmaster, unless the attacker has prior knowledge of queen versus rook end game variations. Notice White’s threat in Diagram-3: immediate mate with Qa4#. If Black now moves Ra6, to prevent that mate, then White would move Qb7, maintaining an eye on c6 and threatening the rook that would be on a6, not to mention the threat of another mate. If Black moves Ka3, in Diagram-3, Qe3+ wins the rook. On the other hand, if the rook moves to b3, White can move Qd5, pinning the rook and winning it. If the black king then moves to a1, the white king may capture the rook without any stalemate (capturing with Qxb3, would be stalemate). Black appears to have only one reasonable move, in the position in Diagram-3: Rb2+. The problem with this check is that it will be the last check available to Black without just throwing away the rook. In Diagram-4, black just moved Rb2+. White now makes the right move: Kc1, which wins quickly. Notice the problem Black has in Diagram-5. It’s not just the threat of Qa4#. The white king is touching the rook, meaning that moving the black king to a3 or b3 allows the queen to win the rook by a skewer tactic. Moving the king to a1 allows White to win quickly after Qd4. In the queen versus rook end game, both sides need to beware and be aware of a check that forces a king to move aside and lose its friendly piece. That’s one kind of skewer. In Diagram-5, if Black moves Ka3, then Qa8+ forces that king to the b-file. The queen can then move Qb7+, forcing that king off the b-file. So what? The queen will then just capture the rook, as the white king would support that capture, protecting the queen from the black king. What if Black moves Rb3 in Diagram-5? It prevents an immediate checkmate from White moving Qa4#. It also allows a mate in three (after Rb3): 1. Qa4+     Ra3 2. Qc2+     Ka1 3. Qb2#     checkmate

Diagram-2: White to move

White will now corner in the black king by Kc2.

Diagram-3: Black to move

Diagram-4: White to move

Diagram-5: Black to move (White just moved Kc1)