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MatPlus.Net Forum Twomovers KoBul Kings - Lacny theme

### KoBul Kings - Lacny theme

KoBul Kings: When a piece (not a pawn) of his own side is captured, a KoBul King transforms into a Royal Piece of the same type as the captured one. When the King is in the form of any Royal Piece and there is a capture of one of the pawns of his own side, he becomes a normal King again.

Jacques Rotenberg
2 Prize, KoBulChess TT/A1 2012
(= 13+9 )

#2 KoBul Kings

1.Rf3? (-)
1...Sxf3[d8=rR] (a) 2.Qc1 (A)
1...Sxe2[d8=rB] (b) 2.rBe7 (B)
1...Sh3 (c) 2.Bxb4[c5=rR] (C)
1...h3!

1.Bf3! (-)
1...Sxf3[d8=rB] (a) 2.rBe7 (B)
1...Se2 (b) 2.Bxb4[c5=rR] (C)
1...Sxh3[d8=rR] (c) 2.Qc1 (A)

This problem is claimed to show the Lacny theme (cyclic shift). However the moves (a), (b) and (c) are not the same between phases, because the the type of white royal piece is different. Also, the above variations can be written as follows:

1...Sg~ 2.Bxb4[c5=rR]
1...SxR[d8=rR] 2.Qc1
1...SxB[d8=rB] 2.rBe7

These variations are the same in both phases, so is there really any change at all?

In my opinion this is a clear example of Lacny theme. Even in ortodox #2 Lacny problem it's very often that in one phase white captures some piece and in another it does not capture piece. This is a nice problem showing Lacny theme.

I think the change of the nature of the royal piece in one phase contrasted by no change in the other phase, is a mechanism by which the Lacny theme is achieved. It is nice example of the theme. But I understand Geoff's viewpoint and there are I think similar mechanisms used in Circe Lacnys also.

Once upon a time Peter Gvozdjak was collecting material for his book Cyclone (published in 2000), concentrating on the Lacny cycle and other similar closed cycles of moves. Then he was making some decisions about what to include and what not. In the introductory part of the book he explains scope of the book. There is even sub-chapter "What you won't find here or the principles of choice" with section "4. The thematic moves must be identical". In this section he weights various definitions of move identity and makes his own choice - the same unit and the same arrival square are determinants of an identical move.

(By the way, the same principle is kept in Cyclone 2, it's text is available as doc file - http://jurajlorinc.com/chess/c2_text_en.doc)

So the KoBul Kings #2 by Jacques Rotenberg is clearly a problem showing Lacny cycle in the understanding of Cyclone.

I am not competent to speak about the cycles, mainly because I'm not interested in their formal aspects in general. But when the economy of thematic mechanism is skilfully achieved due to the cyclic functionality, it's worth of admiration.

bSg1 has 3 available squares to play on with 3 thematic effects on wK, including no-effect when playing onto empty square. bSg1,wRh3 and wBe2 beautifully show the changed effects of the thematic play onto the same squares. Only the squares are important here, because the black play is caused by the Zugzwang in both phases.

Actually, I have written a paragraph in my post above about general aspects of Cyclone problems as far as aesthetic aspects are concerned. But then I have deleted it as I wanted to concentrate on the question "Lacny or not?"

So after all here are my two cents. Formal aspects are undoubtedly important in Cyclone problems. But they alone can hardly be enough for a good problem. Not only formal theme is important, but also the way it is achieved, in terms of strategy of play. There are poor cycles and there are great cycles. Examples (in my view):

Poor: Lacny cycle with too many fairy elements - http://jurajlorinc.com/chess/m276_283.htm#uloha1

Good: 4-fold Lacny cycle in Circe with use of orgue pipes - http://jurajlorinc.com/chess/griexo02.htm#uloha4

Shortly speaking, strategy is very important in Cyclone problems as well and can be a source of aesthetic pleasure on its own. Then hardly anybody can complain about alphabetic hodgepodge.