Zepler doubling is a manoeuvre in

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 disti ...

in which a piece moves along a certain line (rank, file or diagonal), then another friendly piece moves onto that same line, then the first piece moves again in the same direction as before. The term is effectively limited to the field of

chess problem A chess problem, also called a chess composition, is a puzzle set by the composer using chess pieces on a chess board, which presents the solver with a particular task. For instance, a position may be given with the instruction that White is to ...

s. The first problem to show the idea (shown to the right), by Erich Zepler himself, is a simple and clear demonstration of the manoeuvre. The straightforward doubling 1.Rgb2, threatening 2.Rb8#, fails to 1...Bxd6, so the more roundabout Zepler doubling is required: 1.Rb4 Bg7 (now 1...Bxd6 is no good because of 2.Rg8+) 2.Rgb2 any 3.Rb8#. Zepler doubling can be contrasted with another doubling manoeuvre,

Turton doubling Turton doubling is a manoeuvre in chess in which a piece moves along a line (rank, file or diagonal), then a similarly-moving piece moves onto the same line in front of it, then this second piece moves again along this line, in the opposite direc ...

References

* David Hooper and

Kenneth Whyld Kenneth Whyld (6 March 1926 – 11 July 2003) was a British chess author and researcher, best known as the co-author (with David Hooper) of ''The Oxford Companion to Chess'', a single-volume chess reference work in English. Whyld was a str ...

, "Erich Ernest Zepler" in ''

The Oxford Companion to Chess ''The Oxford Companion to Chess'' is a reference book on the game of chess written by David Vincent Hooper and Kenneth Whyld. The book is written in an encyclopedia format. The book belongs to the Oxford Companions series. Details The first e ...

'' (Oxford University Press, 1996) Chess problems 1929 in chess {{chess-stub