Selfmate
Encyclopedia
A selfmate is a chess problem
in which white, moving first, must force black to deliver checkmate within a specified number of moves against his will. Selfmates were once known as sui-mates.
The problem to the right is a relatively simple example. It is by Wolfgang Pauly (from The Theory of Pawn Promotion, 1912) and is a selfmate in 2: White moves first, and compels Black to deliver checkmate on or before move two. Here, if White can leave Black with no option but to play Bxg2#, the problem is solved. White might try moving the bishop, but this is no good, as it will allow Black to play a non-capturing bishop move himself, delaying the mate beyond move two; moving the knight allows the king to move; 1.e6 allows 1...exf6 and 2...f5; 1.f7 or 1.fxe7 allows 1...Kxg7; 1.g8Q or 1.g8R are no good after 1...Bxg2+ 2.Q/Rxg2; 1.g8N checkmates Black, which is entirely wrong; 1.g8B is also no good, since after 1...exf6 2.exf6 Bxg2 the bishop can interpose with 3.Bd5. The only move by which White can force Black to deliver checkmate on or before move two is 1.c8N. There are two variations: 1...exf6 2.exf6 Bxg2# is quite simple; 1...e6 leads to the more subtle 2.g8B Bxg2# (this only works because the bishop's path to d5 was blocked when Black played e6). Note that only a promotion to a knight works on move one: any other piece would be able to interpose after Bxg2.
A derivative of the selfmate is the reflexmate
, in which White compels Black to give mate with the added condition that if either player can give mate, they must (when this condition applies only to Black, it is a semi-reflexmate). There is also the maximummer, in which Black must always make the geometrically longest move available, as measured from square-centre to square-centre; though this condition is sometimes found in other types of problems, it is most common in selfmates. Another variation is the series-selfmate, a type of seriesmover
in which White makes a series of moves without reply, at the end of which Black makes one move and is compelled to give mate.
Chess problem
A chess problem, also called a chess composition, is a puzzle set by somebody using chess pieces on a chess board, that presents the solver with a particular task to be achieved. For instance, a position might be given with the instruction that White is to move first, and checkmate Black in two...
in which white, moving first, must force black to deliver checkmate within a specified number of moves against his will. Selfmates were once known as sui-mates.
The problem to the right is a relatively simple example. It is by Wolfgang Pauly (from The Theory of Pawn Promotion, 1912) and is a selfmate in 2: White moves first, and compels Black to deliver checkmate on or before move two. Here, if White can leave Black with no option but to play Bxg2#, the problem is solved. White might try moving the bishop, but this is no good, as it will allow Black to play a non-capturing bishop move himself, delaying the mate beyond move two; moving the knight allows the king to move; 1.e6 allows 1...exf6 and 2...f5; 1.f7 or 1.fxe7 allows 1...Kxg7; 1.g8Q or 1.g8R are no good after 1...Bxg2+ 2.Q/Rxg2; 1.g8N checkmates Black, which is entirely wrong; 1.g8B is also no good, since after 1...exf6 2.exf6 Bxg2 the bishop can interpose with 3.Bd5. The only move by which White can force Black to deliver checkmate on or before move two is 1.c8N. There are two variations: 1...exf6 2.exf6 Bxg2# is quite simple; 1...e6 leads to the more subtle 2.g8B Bxg2# (this only works because the bishop's path to d5 was blocked when Black played e6). Note that only a promotion to a knight works on move one: any other piece would be able to interpose after Bxg2.
A derivative of the selfmate is the reflexmate
Reflexmate
A reflexmate is a chess problem in which white, moving first, must force black to deliver checkmate within a specified number of moves against his will - with the added condition that if either player can give checkmate, they must. If this condition applies only to Black, it is a semi-reflexmate...
, in which White compels Black to give mate with the added condition that if either player can give mate, they must (when this condition applies only to Black, it is a semi-reflexmate). There is also the maximummer, in which Black must always make the geometrically longest move available, as measured from square-centre to square-centre; though this condition is sometimes found in other types of problems, it is most common in selfmates. Another variation is the series-selfmate, a type of seriesmover
Seriesmover
A seriesmover is a chess problem in which one side makes a series of legal moves without reply at the end of which the other side makes a single move, giving checkmate or yielding stalemate, depending on the precise stipulation. Checks cannot be given except on the last move of the series...
in which White makes a series of moves without reply, at the end of which Black makes one move and is compelled to give mate.