CHANGED MATES

Popular modern problem idea. There are following kinds of mate changes (game changes): – change of checkmates with the same defenses (single mates) in different phases, if there are 2 or more changes in 3 or more phases, we speak about Zagoruyko theme; – change of defenses, which follow the same checkmate (theme Rukhlis); – change of defenses and checkmates (random change of play); – change of defenses, checkmates and themes (radical change of play); – interchange of the checkmates with the same defenses (reciprocal change of mates); in case there are more than two defenses, we speak about the themes Lacny; – synthesis of change types (change Rukhlis, random, single) etc., for instance, theme Stocchi. – synthesis of themes Zagoruyko and Rukhlis (three-phased change of checkmate with one and the same defense; the same checkmate with various defenses) – theme Chepizhni. Changed move-functions. Famous modern idea in two- and three-mover problems. In order to compare the letter algorithms the ideological moves of white are indicated with uppercase letters (A, B, C, ets) and moves of black pieces – with lowercase letters (a, b, c, ets). In case of try threats and refutation connection: 1. Х? (2. A#) a!, 1. Y? (2. B#) b!, Key 1. Z! a / b 2. A# / B# – theme Domdrovskis. 1. Х? (2. A#) a!, 1. Y? (2. B#) b!, Key 1. Z! a / b 2. B# / A# – theme Hannelius. In case of phase key and refutation connection: 1. A? a!, 1. B? b!, Key 1. X! a / b 2. A# / B# – theme Vladimirov. 1. A? a!, 1. B? b!, Key 1. X! a / b 2. B# / A# – theme Banny. If the connection key – mate is considered, the algorithm of themeSalazar is possible: 1. A? a 2. B#, Key 1. B! a 2. A#. The interchange of threat and mates on one and the same defense of two phases creates theme le Grand: 1. X? (2. A#) a 2. B#, Key 1. Y! (2. B#) a 2. A#. In diphase problem the Lender combination with direct and inverse consecution of white moves is famous: 1. A? (2. B#) a / b 2. C# / D#, Key 1. D! (2. C#) a / b 2. B# / A#.

A. LOBUSOV 1^st Prize, “Neue Zürcher Zeitung”, 1998-1999 Mate in 2 moves (8+5) 1. Bh5? [2. Qf3# (A)], 1…Kxf5 (a) 2. Qg4# (B), 1…Kxd5! (b) 1. Bf7? [2. Qg4# (B)], 1…Kxf5 (a) 2. Qf3# (A), 1…Qxd5! (c) – le Grand themes (threat and mates). 1. Bd4! [2. Sf6#], 1…Kxd5 (b) 2. Qf3# (A), 1…Qxd5 (c) 2. Qg4# (B) – Dombrovskis themes (refutation a & b, mates A & B).