Tarrasch trick - R+N draw

Oldies but goldies. It is known that the best place for a rook is the 7th or the 2nd rank if the king of the opposite party is trapped on the back rank. In Tarrasch's "The Game of Chess" it is called one of the "elements". It is now interesting to know that a rook on the 7th/2nd rank together with a knight is able to create a perpetual check - as is shown in the diagram.

Obviously there is no way for White to prevent the promotion of Black's pawn since 1.Nh7+ Ke8 2.Nf6+ Kd8 3.Rd7+ leads to nowhere because the square d1 (from which it would be possible to stop the pawn) is protected by Bf3.

But there is a chance for White to draw with the key move: 1.Rd7! Now, after 1.- f1-Q, White has a "remisschaukel" with 2.Nh7+ Ke8 (2.- Kg8 3.Nf6+ Kh8 4.Rh7#) 3.Nf6+ and draw. The point of Rd7 is to make sure that the black king cannot escape via d8.

I think it is quite useful to know this small trick, though I must admit I never got the chance to use it in an over the board game.

-