There is first of all the law of economy in material which demands that the idea of the problem should be expressed with the least possible number of men, and that no pieces should be added for the mere sake of increasing the number of variations. Then, of course, a problem should have only one solution. A position which has more than one key move is not considered a problem, because the main point at issue in a problem is not the NUMBER of moves in which the mate is accomplished but the METHOD in which it is accomplished, and of two possible solutions one will always be prettier so that the existence of the other must necessarily appear a blemish.
A very important law is that the first move of White (who by general consent has always the attack) must not deprive the black King of a flight square, as this would be too brutal, too obvious a procedure. The more possibilities of defense are left to Black the more surprising is the solution and the finer is the problem.
Many problem solvers are under the false impression that the first move in a problem must not be a check. This argument is valid only when by the check the number of defensive moves is limited, but this is not necessarily the case, as can be seen for instance in problem No. 2, in which Black has to move his King anyway, there being no other black piece on the board.
The position of Diagram 76 is an example of how a problem should NOT be constructed. There is a tremendous number of pieces on the board which have nothing to do with the idea of the problem. The latter is one of the most primitive ideas used in problem composition and has been expressed by many composers in charming forms, so that there was no need for the above monstrous addition to the problem literature. The key move is Q-h7 so as to pin the Rook f5 in case Black plays K-d3 and to enable the mate (2) Rxf3. However, if Black replies (1) …, P-d3 or Bxe1, neither the Queen nor the Rook f4 are necessary, but the mate is accomplished by some of the other white pieces which are lavishly distributed over the board.
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8 | | | | | | | | ^Q |
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7 | | | | | | | | |
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6 | ^Kt| | | | #P | | | |
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5 | | | ^P | | ^P | #R | | |
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4 | ^B | | #P | #P | | ^R | | |
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3 | #P | | #K | | | #P | ^Kt| |
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2 | ^P | | | #B | | ^P | | |
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1 | ^K | #Kt| | ^R | ^B | | | |
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DIAGRAM 76.—Mate in Two Moves
A striking contrast will be found in the following problem which is based on the same idea but in which all unnecessary material is dispensed with.
The key move is B-c1, in order to mate with the Queen on b3 in case Black takes the Rook a3. If Black moves the Rook, White mates by Qxb6, and if the Pawn b6 advances (2) Qxe7 is mate.
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8 | | ^K | | | | | | |
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7 | | | | | #P | ^B | | |
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6 | | #P | | | #Q | | | |
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5 | | | | | ^P | | | |
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4 | | #K | | | | | | |
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3 | ^R | | | | ^B | | | |
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2 | | #R | | | | | | |
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1 | | | | | | | | |
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DIAGRAM 77.—Problem No. 1.