Novotny (chess)

The Novotny (also often spelled as Nowotny, even in non-German sources) is a device found in chess problems named after its discoverer Antonín Novotný. A white piece is sacrificed on a square where it could be taken by two different black pieces - whichever black piece makes the capture, it interferes with the other. It is essentially a Grimshaw brought about by a white sacrifice on the critical square.

This pattern can arise as part of a combination in an actual game, but it is extremely rare (see games below). Most chess players would not use the term "Novotny" to describe such a move, since that term is almost exclusively used in the context of chess problems.

The device can be understood by reference to the problem to the right, a mate in two moves (white moves first, and must checkmate black in two moves against any defence). The key (first move of the solution; see Glossary of chess problems) is 1.Nb2 (see algebraic notation). This interferes with black's rook and bishop, and whichever of those pieces takes the knight, it will interfere with the other—this is the Novotny idea at its most basic. So, if black plays 1...Bxb2, this interferes with his rook and allows 2.Qf2#, while if he plays 1...Rxb2, it is the bishop that is interfered with, allowing 2.Qd4#.

Problemists would generally agree that a single Novotny with no other play, as in this example, makes for a relatively uninteresting problem. Usually, Novotnys are combined in problems with other ideas, or several Novotnys are shown in a single problem.

The problem to the left is very well known. It contains no fewer than six separate Novotnys. It is by R. C. O. Matthews, was published in the British Chess Magazine in 1957 and won the Brian Harley Award. It is a mate in 3.

The key is 1.b4, threatening 2.Bxb1 and 3.Ra3#. Black has six thematic defences, each of which White meets with a Novotny on move two:

The solution, in short form, is thus: 1. b4

Four of White's Novotnys in these variations are executed by the rook on b5—only the rook will do in those variations, because the square it comes from, b5, must be vacated for the white knight to deliver mate. In the other two lines, that rook is captured, meaning it cannot execute the Novotny, but also meaning the square vacation is no longer necessary (the white knight can simply capture the black piece on b5). Therefore, another piece can make the Novotny interference in those lines. (There is one other non-thematic defence in the problem: 1...Nd2, threatening a nuisance check on b3. This allows 2.Ra3+ Nb3+ 3.Rxb3#.)

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