Let’s look at the standard winning method against the Third Rank Defense in the queen versus rook end game. This is a challenging defense to break down.
Diagram-1 of this variation of the queen-versus-rook
Notice the key elements:
- Defending king on the edge, on a center square of that edge
- Queen is a knight’s move away, keeping the defending king on that edge
- The queen keeps the defending king off the other center square of the edge
- Attacking king is opposing the defending king, with two squares intervening
- Rook is blocking the attacking king from getting any loser to defending king
Notice that the queen prevents the defending king from moving to a4, the other edge-center square. This is important in the standard position. Also notice the key element to third-rank defenses in general: The rook cuts off the attacking king by staying on the third file or third rank from the defending king.
The key position in this defense is shown in Diagram-1, and it includes the relationship between defending king and rook: One is two diagonal moves away from the other.
Diagram-2 after Qe3
The queen moves away from the edge where the defending king was confined, landing on the square on which the queen’s diagonal points toward the square between the defending king and the rook. In Diagram-2, this diagonal is from e3 to b6. Black’s best move here is Kb5, as the defending king escapes from the confinement of the edge of the board.
Diagram-3 after Kb5
White’s queen move appears to be a mistake, for it lets the black king escape, but this is only temporary. The queen now moves to e8.
Diagram-4 after Qe8+
After Qe8+, if Black moves Ka5 or Kb4 then the rook will be lost (after Qd8 or Qb8). If Ka6, from Diagram-4, White can move Kd6 and Black will need to play Rc7, which will allow the white king to approach the defending king with Kc6, and Black will soon be trapped, obviously with the Third Rank Defense broken down. Let’s see what happens when Black instead moves Kb6 from Diagram-4.
Diagram-5 after Black moved Kb6
White now forces the rook off the third rank with Qb8+.
Diagram-6 after Qb8+
Black’s only choice for saving the rook is Rb7.
Diagram-7 after Rb7
The defending king is now pushed back to the edge of the board, but this time the Third Rank Defense has been broken and Black should soon be cornered.
Diagram-8 after Qd6+
Now if Ka5 then White can maneuver the queen to a4 (with the black king soon returning to b6) and the white king will move to d6, making an Euwe position, a fairly easy win. In Diagram-8, if Black moves Kb5, White wins the rook with Qc6+.
The only other move available to Black is Ka7, which allows Kc5 for White, an obvious breakdown of the Third Rank Defense. White should soon win this end game.
Thanks to Derek Grimmell for his extensive research in queen-versus-rook end games.
Why show a chess student a position that’s almost the same as one that was already shown to that student? Many small details can make an infinite difference in chess, and these can be created in nearly-identical positions.
Many tens of thousands of books have been written about chess, over the centuries, and most of those were probably published since the beginning of the twentieth century.
Moving Rc8 soon results in a fatal back-rank prison for the black king as follows . . .
[Reviewing two chess books] Besides the covers, with cartoon characters and similar titles, they have something else in common: Both emphasize the importance of tactics in winning chess games.