Rook endgame essentials

More games reach a rook ending than any other kind, and more half-points are dropped there than anywhere else. The good news is that four ideas do most of the work, and two of them are positions you can memorise in ten minutes each.

Idea one: the active rook is worth a pawn

In a rook ending, a rook that attacks is worth more than a rook that defends, by roughly a pawn. Given the choice between holding a pawn with a passive rook and giving up the pawn to get your rook active (checking from behind, attacking their pawns), take the active rook. This single principle decides more club rook endings than all the theory.

Idea two: rooks belong behind passed pawns

Yours or theirs. A rook behind a passed pawn gets stronger as the pawn advances (more squares behind it). A rook in front gets weaker (it has to move out of the way). If the opponent has a passed pawn, get your rook behind it and the pawn is going nowhere. If you have one, put your rook behind it and push.

Idea three: the Lucena position (winning)

Rook and pawn against rook, with your pawn on the seventh and your king in front of it. This is the position every rook ending a pawn up is trying to reach, and it wins with a technique called building a bridge.

The idea: 1.Rf4 (any square on the fourth rank works). Black checks from the side: 1...Ra8+ 2.Kd7 Ra7+ 3.Kd6 Ra6+ 4.Kd5 Ra5+ 5.Rc4? no: 5.Kd4! and the next check is answered by 6.Re4, blocking, and the pawn promotes. The rook on the fourth rank is the bridge the king crosses under. Play it against the engine until your hands know it.

The one thing to remember: the rook goes to the fourth rank first, before the king steps out. Players who step out first walk into perpetual check.

Idea four: the Philidor position (drawing)

Rook and pawn against rook, and you are the one a pawn down, with your king in front of the pawn. This draws, with one rule: keep your rook on the third rank until the pawn gets there, then check from behind.

Why it works: while the pawn is on the fifth, the White king cannot advance past the rook's rank without the pawn's support. The moment the pawn advances to e6 to take that rank away, it also blocks its own king's shelter, and checks from behind have no answer. Black plays 1...Ra1 (or any distant square) only after e6, never before.

Both positions have mirror images and variations. Know these two shapes, and you will recognise the others.

Two more rules, quickly

• Cut the king off. With a passed pawn, a rook that keeps the enemy king one file away from the pawn is worth more than an extra pawn. Files are the currency.
• Check from far away. A rook giving checks needs distance; a rook next to the king gets attacked. Three ranks or files of distance, minimum.

The tell

You are in a rook ending and your rook is defending a pawn from in front, or your king is behind your own passed pawn, or you have let their king in front of your pawn. All three are fixable; all three are worth stopping to fix.

The habit

The moment a rook ending appears: "Is my rook active? Is it behind the passed pawn? Which of the two positions am I heading for?" And then set up Lucena and Philidor against the engine once a month. They will not stay learned any other way.