Since this endgame only has four pieces, it was fully analysed by computers in 1978, and this revealed subtleties overlooked by earlier writers.
[1][6] John Nunn's Secrets of Pawnless Endings splits the ending into four phases:[7] Nunn recommends that the defender try to pass through all four stages, and cautions that prematurely giving up a fourth- or third-rank defense is a common error.
They also add a final stage, consisting of picking up the rook by a fork after Philidor's position has been achieved.
[3] Because of this, a common defensive motif for Black is to put the rook on the same diagonal as White's king to prevent forks.
[8] David Smerdon calls queen versus rook "the most underappreciated endgame in chess", noting that it is often not taught in much detail, despite its commonness.
Not all the lines given are optimal according to the tablebase, because sometimes a slightly longer but more systematic win is more intuitive for human players.
[3] Now Black is in zugzwang, and wherever they move their rook, it will be lost to a series of checks culminating in a fork:[3] Once the rook is lost, the result is a basic checkmate (king and queen against king), which is easily won.
White's goal is thus to create Philidor's position, which involves getting their king on the sixth rank.
[8] 2.Kc6 also theoretically wins just as quickly, but it allows Black to escape into a practically problematic third-rank defense with 2...Re6+.
[3] The stronger side must remain alert to stalemating possibilities from the weaker,[12] which are quite common tries for defense.
[8] Nunn calls attention to a tactic in diagram 2, noting that it is "not obvious": after 1.Qd8 Kh7, it is good to play 2.Qd4 covering g7, so that after 2...Rg7+ 3.Kf6 Rg6+ 4.Kf7 Black will no longer be able to check.
[3] Nunn concurs, drawing a distinction between breaking down the second-rank defense (which he considers a strong player likely able to calculate over the board), versus breaking down the third-rank defense (where he considers that the winning method must be known beforehand).
This is especially so because the defense is easy for Black to hold if White does not know what they are doing; it simply involves keeping the rook on the third rank.
[13] This is relatively easy to force the defending side out of, resulting in a third-rank or second-rank defense.
[14] It is best to avoid 1.Kd4 Ra1, where Black puts the rook on the same diagonal as White's king and threatens to check from two directions.
White would then have to lose time and find several difficult moves: 2.Qf7+ Kd6 3.Qb3 (denying d1 and a4 to the rook) 3...Ke7 4.Qc3 Ra6 5.Qc7+ Kf6 6.Qd8+ and 7.Ke5 will force Black into a third-rank defense.
[14] Nunn singles this out as "the trickiest moment": it allows a shorter (and less effective) diagonal motif, but this cannot be averted because 4.Kd3 runs into 4...Rb1.
[14] Discounting the possibilities of immediately winning the queen, there are a few positions where the rook can draw because the poor placement of the enemy pieces permits stalemate-related tactics.
[15] The White king cannot cross to the e-file (because the queen would be lost to a pin), and the rook is immune to capture on h7 or g6 (e.g. 1...Rg7+ 2.Kf6 Rg6+!
[15] Likewise diagram 2 permits a draw by perpetual check from g7 and h7, because the White king cannot cross to the f-file and cannot capture the rook on h6.
)[15] Finally, diagram 3 has the defending king immobilised in the corner by the enemy queen a knight's move away, so the rook may give perpetual check along the g-file (being immune on g6) or the first rank.
[15] Even grandmasters sometimes fail to properly execute the winning technique, as demonstrated by this 2006 game between Alexander Morozevich and Dmitry Jakovenko.
[9] Black is trying to stop the White king from penetrating using a fourth-rank defense[14] (though the board is rotated 90 degrees here).
[9] A standard motif,[8] going to the diagonal the White king is on in order to avoid getting forked.
[9] The most tenacious defenses often require moving the rook away from the king in such a way that it will be safe from forks.
In this case, Black is safe, because he can either move his king on the dark squares or block checks with his rook.
[16] Black could have held out five moves longer with 82...Kb5; in general, it is better for the defending king to be near an edge than a corner.
Even on a 12×8 board, the Philidor position is already much more complicated if Black moves the rook the furthest possible distance, though the ending is still a general win in this case.
[18] There is a drawing fortress involving a non-rook's pawn on the second rank next to its king and rook.
(The defender has better chances if his king remains on the lower ranks, which forecloses zugzwang possibilities from the attacker.