Rook and rook's-pawn

The key idea

The rook's pawn only has one flank. If the defending king arrives in time, it's a draw against any technique; if it doesn't, the attacking king wins by walking TOWARD the checks, never away from them.

Example 1 · The side defense (Vancura)

The defender doesn't put the rook behind the pawn: they put it SIDEWAYS, attacking it from the sixth rank. That way they keep the checks and the attacker can't touch anything.

1. Kg3 Look first at how the roles are split. The white rook is on a8, in front of its own pawn: it's a frozen piece, it can't move without giving up promotion. All of White's hope is the king, and it's going up to look for trouble.
2. Kh7 The black king steps toward the corner. It doesn't get in its own rook's way and it stays out of the fuss: in this defense, the rook does the work, not the king.
3. Kg4 Keeps climbing. It wants to reach the sixth rank and chase the black rook off it.
4. Rg6+ And here's the heart of the defense: the black rook attacks the a6 pawn FROM THE SIDE, along the sixth rank, and gives check along the way. It's not behind the pawn — that rook would be passive and dead — it's at a distance, hitting and pestering at the same time.
5. Kf5 The white king keeps advancing. It's the only thing left to try: if it moves the a8-rook, the pawn falls; if it doesn't, the pawn doesn't advance.
6. Rd6 The rook slides along the sixth rank, without leaving it. It keeps aiming at a6, keeps its distance from the white king. That rank is its home: as long as it doesn't leave it, the pawn doesn't move.
7. Ke5 The white king tries to hunt it down by getting closer through the center.
8. Rg6 And it steps away to the other end of the same rank. The detail you have to learn: the rook flees ALONG THE SIXTH, never backward. Every square on that rank keeps attacking the pawn.
9. Kd5 The white king goes back to the chase. It can repeat this as many times as it likes: it doesn't get anywhere.
10. Rg5+ Check again, now from the fifth. Whenever the white king steps onto the rook's rank, it drops down one and keeps checking from a distance. This is the other half of the resource: distance. With the white king four files away, the checks never run out.
11. Kd6 There's no plan left. The king moves just to move.
12. Rg6+ And back to the start. Summing up the defender's recipe: rook to the side attacking the pawn (never behind it), own king tucked in the corner, and checks from a distance whenever the enemy king gets close. With that you save half a point against anyone. Draw.

Example 2 · When the defending king doesn't arrive: the rook's pawn wins

Same pawn, same rook in front — but the black king is on g7, too far away. Watch how it's won: the king walks TOWARD the checks until they run out.

1. Rd8 First move and already the most important one: the rook LEAVES a8. It does two things at once — it frees the promotion square and cuts the black king off along the d-file, so it won't be able to cross over to help. The a7 pawn is left alone for an instant, and that instant is enough.
2. Rb2+ Black starts the checks, which is all there is: if the checking stops, the pawn queens. The plan is to push the white king away from the pawn.
3. Kc5 And here's the whole technique in one move: the king does NOT flee the check, it moves toward the rook giving it. Every step toward it costs that rook one more checking square.
4. Rc2+ Second check, along the king's file. Black has nothing else.
5. Kb4 Another step toward the rook. Count the files Black has left to check from: fewer and fewer, because the white king is eating them up.
6. Rb2+ Third check. The strangling is already showing: the rook doesn't know where to go.
7. Kc4 Another step. Notice the king never moves away from the pawn for the fun of it: it comes down diagonally, always staying close enough to get back.
8. Rc2+ Fourth check, and the last one that does anything useful: look where the rook has ended up relative to your king.
9. Kb3 And the ammunition runs out: the white king now attacks the rook on c2. It has to move, and moving means it stops checking.
10. Rh2 The rook runs off as far as possible to check from a distance again. It arrives one move too late.
11. a8=Q Queen. With rook and queen against a lone rook, finishing it off is a matter of a couple more moves. Keep the difference between the two examples: in the first, the black king was in front of the pawn and there was nothing to do; here it was on g7, watching from the stands. That's the WHOLE rook's-pawn ending — measure where the defending king is before deciding what you're playing for.

Practice

You have White in the position from the second example: pawn on a7, your rook in front blocking its own promotion, and the black king too far away to help. Free the pawn and weather the shower of checks until you queen.

1. Two birds with one stone: the promotion square is freed and the black king is cut off on the d-file. Your rook is blocking your own pawn. Get it off the a-file — and cut off the black king along the way.
2. That's it: toward the rook, not away from it. Every step costs Black one more checking square. Don't run from the check toward the edge. Walk TOWARD the rook giving it.
3. Another step. Black is running out of useful files. Same thing again: get closer to the black rook, without letting go of your pawn.
4. Still eating up distance. This is the last check that does Black any good. One more step toward the rook. Come down diagonally, without letting go of your pawn.
5. End of the checks: now it's you attacking the rook. It has to move, and moving lets go of you. Place yourself attacking the checking rook: it can't keep checking and stay safe at the same time.
6. Queen on the board and game won. The black rook has gone far away and arrives one move too late. Queen.

Won the way this ending is won: rook off the pawn's file, king walking toward the checks. And keep the other half of the lesson, the one from Example 1 — with the black king in front of the pawn, this exact same position can't be won with the best technique in the world. Knowing which of the two you're facing is worth more than any trick.