Rook Endings: give me space to check
Check out these two Rook endings. They are identical except for the placement of White's Rook. With Black to move in both cases, in Example 1 Whtie wins but in Example 2 Black draws.
I wanted to understand the difference between the two positions, and this lead me to two great lessons.
See if you can explain the difference yourself before reading on.
Example 1: Black to move, White wins
Taken from Chess Informant Encyclopaedia of Chess Endings Rooks Diagram 59
Example 2: Black to move, draws
Taken from Chess Informant Encyclopaedia of Chess Endings Rooks Diagram 60
Example 1 Explained
Why White wins in Example 1 is that his Rook on a8 controls the Queening square at e8.
Thus when Black attempts to check horizontally and White's King drives the Rook away, he hasn't got time to switch his Rook vertically because White can play e7 threatening to promote.
Example 2 Explained
With the White Rook not at a8, the Queening square is not controlled.
Black gives horizontal checks, and when he is driven can switch to giving vertical checks.
With the White King drawn away from the pawn (due to chasing the Rook), Black threatens to bring his King to attack the pawn.
Instructive from this are the two lessons are learnt.
Lesson 1: Take the a-file as it gives you space for horizontal checks.
Here White had played Rf1 to cut off the White Black King.
However, this allows ... Ra2 and by taking the a-file, the Black Rook has space to give horizontal checks and not be driven back.
Lesson 2: Use the King to harrass the pawns and the Rook to harrass the King
Initially I had played ... Re2 here which would have won for White as his King can reach e8 and build a bridge.
Instructive is to delineate the two roles of the Black's pieces.
The Black King should be used to attack the pawn with ... Kf7, whilst the Black Rook left to harrass the White King should it attempt to shepherd his pawn.