Black Retro „Duals“
by Günther Weeth, Stuttgart
Even after more than a century of the composition of retro problems we are confronted with a certain problem, strange as it might appear to most of us. It shows off when it comes to the evaluation of defensive retractors.
Some retro experts strictly representing no other style than the classical orthodox one, thus being exclusively committed with the aesthetic demands of help retro play sometimes seem to be mistaken when it comes to evaluate defensive retractors. Every now and then you may come across their verdict on black retro moves obviously being ambiguous. Here an example: retro wKc4-c3, bPb7-b5+/bPb6-b5+. A similar move is made in a top class defensive retractor once composed by no less an author than Wolfgang Dittmann, and – according to his report – that move was clearly reprimanded by the judge. Small wonder, – it appears to be an automatic reflex when such an expert is alarmed: “But this is a dual; it lowers the value of the problem….”
How to explain such a reaction?
Orthodox specialists in the field of retro art with their inborn love of classical retroanalysis are accustomed to demand a series of absolutely dual-free moves on either side in the exact shortest proof game as well as in such release problems where a certain number of initial dual-free moves are required (last n moves?). In any such case we deal with help play. And as in forward help play, here any non-uniqueness is to be considered as a dual or a cook.
But in any defensive retractor, no matter whether orthodox or fairy, the situation is entirely different from the above mentioned one. If a black reply to a white retro move is not meant to lead to variants in the white retro play to continue, i.e. if the kind of that black single move does in no way differentiate the series of moves to follow, that black single move does not at all need to be unambiguous. Such a move simply has got to be legal. This is the very same situation as in forward direct mates or studies.
In order to make my point clear let me quote one sample composed by the acknowledged master of the defensive retractor and chosen from the mass of retractors with the same alleged “duals”. Beside its actual thematic intention, the problem quite obviously shows arbitrary black retro moves as we are wont to recognize them in direct forward play where they are marked as “any” in the quotation of the solution.
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Wolfgang Dittmann
Die Schwalbe 1979 1st Prize  -4 & #1 Proca retractor (10+6) |
1.f5:e6 e.p., e7-e5 2.Bg8:Rh7! Rh8:P(S,B,R,Q)h7+ 3.Re5-b5! Kb5-a6 (or Kb5:S/Ra6) 4.Bd5-g8+ – fw.1.L:b7#. (not 2.Bg8:P(Q,B,S)h7??) Here we see no less than two weighty alleged „duals“. The significance of the 2nd arbitrary move is just given by the observation of the law of legality in abolishing the white self-check. The purpose of these lines would be fulfilled if they helped to do away with the reproach of such alleged „duals“ once forever. All friends of retro art are invited to comment on the issue of this article which does not at all refer to matters of subjective taste but rather deals with the fundamental need of preserving all experts’ unanimity in utilizing the same parameters of judgement in tourneys of the future. |
Why not first 1.Bg8:Rh7?
1.Bg8:Rh7? Rh8xBh7! refutes because now
2.f5xe6 e.p. would be illegal for White.
After 1.f5xe6 e.p. e7-e5 2.Bg8xRh7! Rh8xBh7?? would now be illegal for Black.
Yes, you are right, thanks for the explanation. But then it is not correct notation Rh8:P(S,B,R,Q)h7+, should be free of B.
Of course, especially since the deepest and most spectacular part is exactly the (il)legality of uncapture of wBh7.
White must make it illegal, otherwise retracting fxe6ep. would be illegal and retro-opening of the line g8-d5 would be impossible (at least in due time).
I agree with the author’s assessment: a random black retraction move by the same piece in a defensive retractor can’t be considered as a “dual”.
I have recently seen a similar comment in PDB regarding a Proca Retractor composed by Thierry le Gleuher (PDB=P1012572), where Black has an alternate option at the 19th move which was acknowledged as a “dual” by the author. In that case, the alternate retraction is made by a different black piece (a pawn instead of a Rook). In spite of this ambiguous black retraction, the problem still earned a very high recognition.
A judge must apply his own reasoning and common sense in a particular context and ask whether the so-called dual obscures the intended play or not in order to state its impact on the intrinsic value of the composition.
In Wolfgang Dittmann’s above quoted composition it is crystal clear that such alternate options do not harm at all the clarity of the idea.
Isn’t this basically the same discussion as black ‘duals’ in selfmates?
That was exactly my thought, Joost!