The study
Richard Réti published this study in 1921. At first sight White is lost. The h5 pawn needs four moves to promote, and the white king on h8 is far outside its square. The black king, meanwhile, is two moves from capturing the c6 pawn.
Yet White draws, and the idea behind the draw is known as the Réti manoeuvre: a king that pursues two goals with the same moves.
Two goals with one route
A king needs as many moves to travel diagonally as it does to travel straight. So the route h8-g7-f6-e5 takes the king towards the h-pawn and towards its own c-pawn at the same time.
Black has to choose. If the h-pawn runs, the white king reaches d6 or e7 and supports the c-pawn, and both sides make a queen. If the black king spends time taking the c-pawn, the white king steps into the square of the h-pawn and catches it.
The tablebase confirms that Kg7 is the only drawing move at the start, and the precision continues: after 1.Kg7 h4 only 2.Kf6 draws, and after 2...Kb6 only 3.Ke5 draws.
Typical mistakes
Chasing the pawn down the h-file with Kh7 is too slow and loses. Pushing c7 at once also loses, because the black king catches the pawn on b7 or c8 while the h-pawn runs.
The idea appears in practical endings too. Before you give up a pawn race as lost, count your king's moves along the diagonals.
Remember
- Walk the diagonal
- Chase two goals with one route
- Threaten to support your own pawn
- Catch the pawn if your own pawn falls