What do the following eight positions have in common (besides two general facts: queen-vs-rook and in-the-corner)?
Diagram-6 (only two more after this one)
Diagram-8 (basically the same pattern as the other seven)
Each of these eight positions is a Philidor queen-vs-rook corner position. In essence, there are not eight versions of the Philidor, nor four versions with reflections nor even two with double reflections: Each is the same pattern, the same Q-vs-R Philidor. How should we define this pattern?
We could define it thus:
- The defending rook is one diagonal-move from a corner
- The attacking king is two diagonal-moves from that same corner
- The queen is a knight’s move away from both its king and the rook
- The defending king is next to both that corner and the rook but is not in check
Set up those four pieces according to the above instructions and you’ve got one of the eight positions. All Philidor positions (in Q-vs-R) have something else in common, although it cannot be seen by staring at the board. The essence of the position is this: defender to move. The side having the move is at a disadvantage, although the attacker has a way to transfer the move back to the defender, who does not have that luxury of transfer. In other words, when the attacker has the move the queen triangulates to make it the defender’s turn to move, and that position is a zugzwang for the side with the rook.
The details of how the attacker wins against any of the defender’s move-choices—that we leave for another time. For now, to be brief, the rook needs to run away, yet the queen can check the defending king, as necessary, and hunt down that rook.
One of two end-point positions in the QvR endgame
Let’s examine a particular corner defense in the queen-vs-rook chess end game. [not the Philidor]
“Take the lessons in this book seriously and your ability to play chess may advance further than if you had struggled through losing twenty games.”
Stories, legends, documented games and ones that sprang up in the twilight of a romantic imagination—those can be found in films in which chess has creeped through a back door or taken over the whole story.
Learn about the opposition in king-pawn end games.