When the defending king is on an edge of the board, in the queen versus rook end game, one defense is using the rook to cut off the attacking king. It can be critical for the defender to prevent the opponent’s king from coming into king-opposition when the defending king is on the edge. Let’s look at the Absolute Seventh (named by Derek Grimmell).
In Diagram-1, what if it were white’s move? The black king has no move and it partly cuts off its rook. If it weren’t for that rook’s position, cutting off the white king, the attacker might move Kc5 (threatening two mates).
Move Kb6, for black would have few options other than adopting a distant defense. But be aware that the point is not to prevent Ra6+. Indeed, with the white king on b6, Ra6+ could not be answered by capturing that rook, for it would be stalemate. No, the point of Kb6 is that it maintains king contact with c5, where the attacking king wants to go.
Kd6 looks inferior to Kb6, for if the black rook runs far to the right then the white king would be better placed at b6 for it would cut off the black king from running up towards b6 and it might leave more room for the queen to maneuver.
But it’s black’s move in Diagram-1.
Diagram-1 (black to move)
Where can you put the rook? It needs to stay on the fifth rank to keep the white king away, and the following two moves lose the rook:
- Rf5 loses it quickly to Qc2+
- Rg5 loses it almost as quickly to Qd4+, with a queen fork on the next move
So Rh5 is the only reasonable move with the rook.
Diagram-2 (black just moved the rook to h5)
What if the white queen now moves to d5, preparing to get into a forking position? Notice what would happen if the black king tried to escape up the a-file. At a6, it would be in direct opposition to the white king, allowing the queen to check on the a-file. After the rook would interpose at a5, the queen would then move to the b-file with unstoppable mating threats. So the black king needs to move to the third rank after Qd4+.
Diagram-3 (white moved Qd4+)
Keeping in mind that a6 is not where the defending king wants to end up, Ka5 is not an option in the position shown in Diagram-3, for the only other response to white’s then moving Qd2+ is Ka4, which allows a fork with Qd1+. Black’s only reasonable option now appears to be Ka3.
Diagram-4 (black moved Ka3)
What should white be looking for? By moving the queen to e3 and then to f4, the black king would be forced up to a5, to avoid the forking squares e2 and f3. The queen first eliminates the second rank and then the third rank, as acceptable ranks for the black king. This results in the black king being driven to a5, after the queen reaching f4. From the position in Diagram-4, the moves are Qe3+, Kb4 (or Ka4), Qf4+, Ka5.
Diagram-5 (a few moves later; white to move and win)
We have at least ways to win in the position shown in Diagram-5. The quickest appears to be with Qd2+, forking the rook on the next move. But if all the pieces were two squares further down (with the queen on f2, the rook on h3, etc.), that maneuver would not be available, so it’s good to know another way to win here. Do you see the move? It does not involve the queen moving to the second or third ranks.
Diagram-6 (white moved Qf3)
This subtle but winning move by white (Qf3) is not the fastest way to win the rook, but the maneuver works in similar positions where the faster way is not available. Notice that white now threatens the rook and mate at a3. What about Rh4? That only delays mate a few moves, for the queen would move to a3, c5, and b6.
Black’s only option, in Diagram-6, is to check the white king with Rh6+. Yet white’s king then moves to c5 and the game is practically over. The only apparent escape for black, in that case (after Rh6+, Kc5), would be Ka4, but that would allow Qf4+, forking the rook.
Thank you to Derek Grimmell for his deep research into queen-versus-rook end games and for his many Youtube videos that explain the many ramifications, including the special characteristics of the Absolute Seventh.
The essence of the Philidor position in the queen versus rook endgame
Let’s begin this kind of endgame study with defense: How do you draw when you have only a rook and king and your opponent has only a queen and king?
“If you know the chess rules but almost nothing about how to win, this book is for you.” [from the book ‘Beat That Kid in Chess’]
The producers of this film became acquainted as they played chess together. In the movie, the game is shown in a city chess club . . .
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