The Réti endgame study is a

chess Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to dist ...

endgame study In the game of chess, an endgame study, or just study, is a composed position—that is, one that has been made up rather than played in an actual game—presented as a sort of puzzle, in which the aim of the solver is to find the essentially uniq ...

Richard Réti Richard Selig Réti (28 May 1889 – 6 June 1929) was an Austro-Hungarian, later Czechoslovakian, chess player, chess author, and composer of endgame studies. He was one of the principal proponents of hypermodernism in chess. With the ex ...

. It was published in 1921 in '' Kagans Neueste Schachnachrichten''. It demonstrates how a

king King is the title given to a male monarch in a variety of contexts. The female equivalent is queen regnant, queen, which title is also given to the queen consort, consort of a king. *In the context of prehistory, antiquity and contempora ...

can make multiple threats and how it can take more than one path to a given location, using the same number of moves. It is covered in many books on the endgame (see

chess endgame literature Chess endgame literature refers to books and magazines about chess endgames. A bibliography of endgame books is below. Many chess masters have contributed to the theory of endgames over the centuries, including Ruy López de Segura, François-A ...

). The procedure is known as the "Réti Maneuver" or "Réti's Idea". Endgame composer Abram Gurvich called the theme "The Hunt of Two Hares" and it appears in many other studies and games. It is also called "chasing two birds at once".

The study

White is to move and

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in this position. At first inspection, it appears that White has no hope in drawing. His king is well outside the "square" of the black

pawn Pawn most often refers to: * Pawn (chess), the weakest and most numerous piece in the game * Pawnbroker or pawnshop, a business that provides loans by taking personal property as collateral Pawn may also refer to: Places * Pawn, Oregon, an his ...

(see king and pawn versus king endgame) and the king is a long way from supporting his own pawn. However, White can draw by making king moves that have dual purposes. One goal is getting in the square of the black pawn, so it can be intercepted, and the other is getting to the d6 square to support the

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of his pawn. The black king will have to spend two tempi to stop the white pawn from promoting, and this is the number of tempi the white king needs to gain in order to get into the square of the black pawn. The second diagram shows the number of ways that the white king can get to various squares in the minimum number of moves. There are nine ways to get to d6, but only one of them allows him to get into the square of the black pawn. The solution is for the white king to follow the path on the diagonal marked by "1" and then follow the dots to intercept the black pawn (if necessary): :1. Kg7 h4 1...Kb6 transposes. :2. Kf6 Kb6 Black has to spend a tempo on preventing the white king from reaching his pawn. If 2...h3 then 3.Ke7 h2 4.c7 Kb7 5.Kd7 and both pawns promote, with a drawn position. :3. Ke5! Kxc6 Black has to spend another tempo to the pawn, to prevent the white king from protecting it. If 3...h3 then 4.Kd6 h2 5.c7 h1=Q 6.c8=Q, draw. Now the white king has gained enough tempi to get in the square of the black pawn and intercept it. :4. Kf4 Draw, since the white king can stop the pawn from promoting (e.g. 4...h3 5.Kg3 h2 6.Kxh2).

Another study with the same idea

Réti used the same idea in another study. The solution is: : 1. Kg6 Kb6 : 2. Kxg7 f5 : 3. Kf6! f4 : 4. Ke5 f3 : 5. Kd6 f2 : 6. c7 f1=Q : 7. c8=Q Qf4+ : 8. Kd5

Examples from games

Yates versus Marshall

In this game between Frederick Yates and Frank Marshall, Black draws using the same idea: :60... Kb2! If 60...Kc2 61.f4 wins. :61. Kxa4 If 61.f4 then 61...a3 wins. :61... Kc3! :62. f4 Kd4 ½–½.

Lasker versus Tarrasch

In this 1914 game between

World Champion A world championship is generally an international competition open to elite competitors from around the world, representing their nations, and winning such an event will be considered the highest or near highest achievement in the sport, game, ...

Emanuel Lasker Emanuel Lasker (; December 24, 1868 – January 11, 1941) was a German chess player, mathematician, and philosopher who was World Chess Champion for 27 years, from 1894 to 1921, the longest reign of any officially recognised World Chess Cham ...

and

Siegbert Tarrasch Siegbert Tarrasch (; 5 March 1862 – 17 February 1934) was a German chess player, considered to have been among the strongest players and most influential theoreticians of the late 19th and early 20th century. Life Tarrasch was born in Bresla ...

, Black exchanged down into this position because he thought it was a win, but White used the maneuver above to draw the game. :40. h4 Kg4 41. Kg6! Threatening 42.h5. Black had only considered the line 41.Kf6? c4 42.bxc4 bxc4 43.Ke5 c3 44.bxc3 a4 45.Kd4 a3, winning. :41... Kxh4 This move is and the white king gains a tempo to return on a different diagonal which is not obstructed by his pawns. :42. Kf5 Kg3 43. Ke4 Kf2 44. Kd5 Ke3 45. Kxc5 Kd3 46. Kxb5 Kc2 47. Kxa5 Kxb3 ½–½ The theme of this endgame was used later by Réti in the study.

References