No.1576
Armin Geister & Daniel Papack
(Germany)

Original Fairy problems
JF-2020-II:
01.07.2020 - 31.12.2020


Definitions / Определения


No. 1576 Armin Geister &
Daniel Papack

Germany
original - 31.12.2020

white Qc1 Pf2g3f4 Rf1a2 Bg1g6 Kh2 Sa5 black Rg2b3 Kh3 Ph4 Bh7b6 Qe7 Sc8b1
#3            b) Sa5-->d4            10+9
Mars Circe

Solution: (click to show/hide)


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Vlaicu Crisan
Vlaicu Crisan
December 31, 2020 13:16

One of the best Mars Circe direct compositions I have seen in many years. The whole play – including the threat, tries and mates – is based on specific effects.
The position of the wS dictates the right continuation in the variations. The dual avoidance is the best feature of the problem and deserves to be fully explained in order to understand properly the right choice of the white second move.
Any move of wRf1 will create the threat 3.Bg6:g2 (via f1). The wRf1 can’t go to d1, because it occupies wQ rebirth square and will therefore gives the black King the flight g4. So, there are actually only two available options for the wR: c1 and e1.
In twin a) we have:
1… Sa7 2.Rc1? Sd2! and now 3.Kh2:d2 (via e1)?? is illegal due to the guard of d2 from bQ while 3.Bg1:d2 (via c1)?? is not possible due to the occupation of wB rebirth square
1… Sd6 2.Re1? Sd2! and now 3.Kh2:d2 (via e1)?? is not possible due to the occupation of wK rebirth square while 3.Bg1:d2 (via c1)?? is not mate, because black can play 3…Rb3:a5 (via a8)
In twin b) we have:
1… Sa7 2.Re1? Sd2! and now 3.Kh2:d2 (via e1)?? is not possible due to the occupation of wK rebirth square while 3.Bg1:d2 (via c1)?? is not mate, because black can play 3…Qe7:d4 (via d8)
1… Sd6 2.Rc1? Sd2! and now 3.Bg1:d2 (via c1)?? is not possible due to the occupation of wB rebirth square while 3.Kh2:d2 (via e1)?? is not mate, because black can play 3…Rb3:a2 (via a8)
Now we should try to understand why any Black move of bSc8 parries the threat. Initially the bRg2 is pinned by wPg3. After the first Black move, if White executes the threat 2.g4, then Black will be able to play 2…Bh7:g4 (via c8) and after 3.Kg3 Rh2! and the unpinned black Rook interferes just in time.

Nikola Predrag
Nikola Predrag
December 31, 2020 14:17

Yes, rich&deep. And the logic of the key can be gradually built through the tries which introduce the refutations that become defenses in the solution.
Plan relies on 1.g4?(2.Kg3#) Rb3-g3!, so bRb3 must be cut off by a key to prepare 2.g4
1.Qc3?(Qxb3?) does that but both 1…Sa7/Sd6! parry the threat (vacating c8) and refute because after 2.Re1(c1) Qe2(e1) 3.Bxg2+ Qf1!-parries the check. This introduces the defensive motif of 2…Sb1-d2=access to f1.
The key 1.Qe3 interferes with both Rb3$Qe7, turning the ‘dual refutation’ into the anti-dual defense.
Refutation relies on the single departure effect 1…Sc8~ with irrelevant arrival of bS. In the solution, the arrival is still not relevant for parrying the threat 2.g4 but has a respective harmful line-closing effect that creates the thematic content.
Actually, no dual continuation (in B2) is avoided, the arrival of bS actively creates one unique possibility for White. After 1.Qe3, removing bSc8 from the board does not create dualistic #2 (hypothetical 1…Sc8~ would refute).

Last edited 18 days ago by Nikola Predrag
Kjell Widlert
Kjell Widlert
January 16, 2021 18:28

Nobody mentioned the theme of reciprocally changed continuations … perhaps it’s too obvious to mention?