Three against two on the same flank — how the defender holds

Draw White to move · Rook endgames · Difficulty about Elo 1600

The plan

Rook and three pawns against rook and two pawns, all on the same flank — the most common rook endgame in tournament practice, and objectively a draw. The extra pawn is no use, because three against two cannot be forced into a passed pawn as long as the defender does three things. First: the rook goes forward, to the seventh rank behind the enemy pawns — from there it ties them down instead of guarding at home. Second: the king stays with its own pawn and in the corner; any trip towards the centre costs the pawn and the game. Third: if the opponent pushes a pawn, it gets traded — one pair fewer, and the fortress is finally sealed. What the calculation has brought to light is the ranking of these three rules: the only real danger here is the KING. After the in-between check, only two of six replies hold, and the same wrong step loses again later — while even the passive rook move still holds the draw.

Rule of thumb: three against two is a draw — rook forward, king with its pawn, and trade off at the first advance.

Why this level: The most common rook endgame in practice — the piece count doesn't make it harder, just bigger

The solution, move by move

1. 1. Rb7 The rook first. From the seventh rank it ties down the enemy pawns instead of watching its own from behind. Staying at home still holds here too — Rf1, Rg1 and Rb2 are all measured to be within the draw window — but it leaves the whole game to the opponent.
2. 1… Ra2+ The in-between check. It looks harmless and is the sharpest moment of the game.
3. 2. Kg1 The key move: only two of six replies hold — the king has to stay on g1 or h1, that is, with its h-pawn. Kf1 and Kf3 both lose (sideline), Kh3 is mated in two, and interposing the rook on b2 also ends in mate.
   Sideline 2. Kf1 The move that really loses this position: the king gets 'out of the way' of the check and leaves its h-pawn behind while doing so. The oracle then gives Black a good eight pawns' worth of advantage. (Kf3 is even worse, over ten pawns, and Kh3 and Rb2 get mated.) 2… Rxh2 The pawn falls without a fight — and with three passed pawns against one, the defence is over.
4. 2… h4 Black looks for the breakthrough on the edge — the only way to turn the majority into a passed pawn.
5. 3. gxh4 And right now comes the trade. After the recapture only seven pieces remain on the board — from here every further move of this lesson is tablebase-exact, not just engine-backed.
6. 3… gxh4
7. 4. Rb4 The rook forward again: from the fourth rank it attacks the passed pawn and cuts off the king. The king, meanwhile, still may not go for a walk — Kf1 loses here too (sideline).
   Sideline 4. Kf1 The same mistake a second time, now in the tablebase zone: the king lets go of its pawn. Of the seventeen moves in this position, eleven hold the draw — this one is not among them. 4… Rxh2 The h-pawn falls again, and this time it is exact: won for Black. 5. Kg1 Ra2 Two connected passed pawns and an active rook against the bare rook — there is no fortress against that any more.
8. 4… h3
9. 5. Rb3 And now behind it. The rook behind the enemy passed pawn — the same Tarrasch rule as in the outside-passed-pawn lesson, just seen from the defender's side.
10. 5… f4
11. 6. Rxh3 The first extra pawn falls.
12. 6… f3
13. 7. Rxf3 And the second. The pawn advantage has come to nothing.
14. 7… Ra1+ The last try: Black wants to trade rooks and hopes for the pawn endgame.
15. 8. Rf1
16. 8… Rxf1+
17. 9. Kxf1 A draw — and White even ends up a pawn up. That changes nothing either: the black king stands in front of the rook pawn in time. That is exactly the lesson of the whole piece: in the rook endgame, activity and king position count, not pawns.

More in Rook endgames

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