Active and passive rooks
From a1 the white rook guards the a-pawn and supports its advance, and every step the pawn takes gives the rook more room. Black's rook on a7 has the opposite job: it has to block the pawn, and the further the pawn goes, the less it can do.
With the rooks the other way round, the white rook in front of the pawn on a8 and the black rook behind it on a2, the same pawns only draw. Then it is White's rook that is tied down.
The plan
1.Ra4 keeps the rook behind the pawn and also guards the h4 pawn along the fourth rank. That frees the white king, which walks across to the a-pawn: Kf4, Ke4, Kd5, Kc5 and Kb6. Black's checks only slow it down.
If the black king sets off after the a-pawn instead, it leaves its own h-pawn behind. Black cannot cover both sides at once.
Typical mistakes
In the starting position every rook move that leaves the a-file throws the win away. The rook's place is behind the pawn.
The pawn does not need to hurry. In the line shown, a7 comes only once the king stands on b6 to support it.
Remember
- Put your rook behind the passed pawn
- Keep the enemy rook passive in front
- Free the king and march it over
- Push when the king supports the pawn