No.526 by Petko A. Petkov – An excellent Disparate composition, model mates, thematic try-play and instructive detailed comment by the author! The problem is dedicated to me, with author’s comment “in a honor of the two-years anniversary of Julia’sFairies website and successful creative work”.
Thank you so much, dear Petko! (JV)
Disparate: If one side makes a move with a piece of type “x” (black, white, neutral, half-neutral, etc., King included), the other side cannot answer immediately by moving a piece of the same type “x”. (For example: white Qc1, black Ka8,Qa7 – mate in 1 move. After 1.Qc8#, Black is mated because 1…Qb8? is illegal. The mate is possible also with the neutral nQc1 – after 1.nQc8#. Black cannot move the same neutral Queen.) Every Pawn’s promotion is a Pawn’s move, therefore after such promotion (into any possible piece) the other side cannot answer immediately with its Pawn. We can say that after the move of the figure of type “x” any enemy figure of type “x” falls under Half-moving paralysis. This paralysis disappears immediately on the next half-move, if the opponent plays with another piece of type “y”. (This way it is implemented in Popeye. Another implementation of Disparate you can find in WinChloe, but it is based on the different rules. )
No.526 Petko A. Petkov
original – 10.04.2014
Dedicated to Julia Vysotska!
hs#3 b) White Rh7 (7+1+2)
a) 1.nRg4-g8! (Creation of a special neutral Disparate battery nBh6/nRg8 – now the w.King is not under check because the nRg8 – as a rear battery piece, is paralyzed for Black)
1…nBh6-f4 +! (Play of the battery nBh6/nRg8 with activation of nRg8 for Black – the wK is under check!)
2.nRg8-a8!! ( Critical nR-move with a new half-paralyze of nRa8 for Black)
2…nBf4-b8!! (Creation of an Indian neutral battery nB/nR)
3.Sd7-e5 +! nBb8xe5 #! – Mate to the w.K because the nBe5 is paralyzed for White and 4.nBb8?? is impossible). Pay attention that in a final 4.Bg8?? is illegal because Bh7 is paralyzed by the nBe5!
Thematical tries: 1. nBg7? nRg2+! 2.nBa1!! nRb2!! 3.Sb8+? but here 3…nRxb8?? is no mate, because White has a thematical answer: 4.Bg8!! – now nRa8 is closed and nBa1 is paralyzed from the w.Bishop!!; 1.nBf4? is false because now after 1…nRg8+? the w.King is under check, the nR is paralyzed for White and the move nRa8?? is illegal
b) 1.nBh6 – g7! (Creation of a special neutral Disparate battery nRg4/nBb7 – now the w.King is not under check because the nBg7 – as a rear battery piece, is paralyzed for Black)
1…nRg4- g2 +! (Play of the battery nRg2/nBg7 with activation of nBg7 for Black – the wK is under check!)
2.nBg7 – a1!! (Critical nB-move with a new half-paralyze of nBa1 for Black)
2…nRg2-b2!! (Creation of an Indian neutral battery nR/nB)
3.Sd7-b8 +! nRb2xb8 #! – Mate to the w.K because the nRb8 is paralyzed for White and 4.nRb2?? is impossible). Pay attention that in final 4.Rg7?? is illegal because Rh7 is paralyzed from the nRb8!
Thematical tries: 1. nRg8? nBf4+! 2.nRa8!! nBb8!! 3.Se5+? but here 3…nBxe5?? is no mate, because White has a thematical answer: 4.Rg7!! – now nBe5 is closed and nRa8 is paralyzed from the w. Rook!!; 1.nRg2? is false because now after 1…nBg7+? the w.King is under check, the nB is paralyzed for White and the move nBa1?? is illegal!
At the first glance in this problem is used a well known old mechanism for creation of reciprocal Indian batteries R/B that we can see even in the first helpmates in the history of Chess composition (created only with black or white pieces). But in my opinion, this conclusion is not plausible – it is probably only an optical illusion.
Here the Indian theme with neutral figures is double complicated: The “classic Indian” in this Meredith is realized not with 2 half-moves but with 4 half-moves (!!) combined with double roundabout maneuvers of neutral figures. Moreover – as the introduction of the Indian theme, here is created also another new special Disparate battery. The thematic try-play is of course another fresh element (realized in this problem for the first time!) specifical for this unusual condition! The finals are model mates.
As all my Disparate problems, this composition is composed using Popeye’s implementation of Disparate (C+ with Popeye 4,65). (Author)