Not all key patterns or key forms will evolve into a Philidor position, in the queen-versus-rook end game, when the winning side uses the best technique. The following attacks and defenses are exceptions to a fateful evolution into a Philidor.
- Absolute Seventh
- Distant Defense
- Harassing Defense
- Wishbone position
- Javelin position
The above is not meant to be an exhaustive list, just some obvious ones, and it is possible that one or more of the above patterns might eventually become a Philidor.
What’s the difference between a Distant Defense and a Harassing one? They appear similar, but the point is this:
The defender shoves the rook far away from the defending king, with a possibility of bringing it back to close proximity when appropriate. This is sometimes done when nothing else appears feasible, such as when the defending king is hemmed in on or near the edge of the board and no other move seems to work. The rook may be on a file or rank convenient to returning to be close to the defending king.
The rook is used to check the attacking king as much as possible, preventing the attacker from attacking the defending king. Sometimes the rook may hide in the shadow-diagonal of the attacking king, making it difficult for the queen to get a fork. This defense usually arising out of the defender’s purposefully placing the rook where it can make trouble, even if a close defense is feasible.
The Harassing Defense can be the most difficult for the attacker to deal with, yet if the defender makes a slip then it can be hard, if not impossible, to reunite the rook and the defending king.
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.
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.
Each of these eight positions is a Philidor queen-vs-rook corner position. In essence, there are not eight versions of the Philidor . . . Each is the same pattern, the same Q-vs-R Philidor . . .