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No.1427 |
Original Fairy problems |
Definition: (click to show/hide)
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No.1427 Chris Feather |
Solutions: (click to show/hide) |
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white Kf7 Sa3 Bh6 Pa4
black Kd3 Rc3 Be2 Pd4e4g6h7
h#2.5 b) Pa4?g2 (4+7) |
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No.1427 |
Original Fairy problems |
Definition: (click to show/hide)
|
No.1427 Chris Feather |
Solutions: (click to show/hide) |
|
white Kf7 Sa3 Bh6 Pa4
black Kd3 Rc3 Be2 Pd4e4g6h7
h#2.5 b) Pa4?g2 (4+7) |
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“Such an interchange may bit immediately be reversed by the other side.” — Is this right? I think it should be “Such an interchange may NOT immediately be reversed by the other side”.
I agree – it is *not* legal to immediately reverse a Messigny interchange (otherwise, White could never perform such an interchange in direct play, because Black could always restore the previous situation by changing back).
… and the mates in No.1427 wouldn’t be mates!
Miniature:
8/5P2/8/4K3/5B2/N1rk4/4b3/8
h#1.5 2 solutions 4+3
1…f7-f8=R 2.Rc3-b3 Rf8Rb3 #
1…f7-f8=B 2.Be2-f1 Bf8Bf1 #
[img]http://www.yacpdb.org/xfen/?8/5P2/8/4K3/5B2/N1rk4/4b3/8[/img]
white first move in feather original has an interesting thematic motivation with a good dual avoidance. Losing this does not make the problem better
I agree here, too: beside the mating Messigny interchange, 1427 has the points “where to put the wK, f8 or g7?” and “why not interchange the solutions of a) and b)?”. The miniature version is much less interesting.
The miniature is just an illustration of the condition. That’s just the scheme from where the composing only begins (as it was probably the case with CJF).
Having bR or bB (respectively) merely to allow the place exchange and nothing more in that one phase, is a poor excuse for introducing a fairy condition.
Just a rough orthodox example:
White Pd7 Ph7 Sg6 Se5 Bc4 Kb2
Black Bc5 Kd4 Re4
Stipulation H#1.5
Twin Move e5 g2
Dual is avoided by the twinning (“why not interchange the solutions of a) and b)?”).
It could be done by the play, with reciprocally useful wPs, enabling model mates:
White Kg8 Pe4 Bc3 Pb2
Black Pf7 Pa5 Sb5 Rc5 Kc4 Bb3 Pd3
Stipulation H#2.5
Condition MessignyChess
1…Kg7 2.Pf7Pb2! f8R! 3.Rc6 Rf8Rc6#
1…Kh8 2.Pf7Pe4! f8B! 3.Ba2 Bf8Ba2#
There is no big difference between “by the twinning” and “by the play” in cases like this: in Feather’s position, White must avoid the line of play that results in a mate on the square that the Messigny interchange will guard; in Predrag’s position, Black must choose the line of play that unguards a flight that the mate by Messigny interchange will guard. So in short, the real difference is that Predrag has unguard of a flight where Feather has guard of a mating-square.
The version is quite interesting, and the model mates are a real plus.
There is certainly a big difference, especially in case of convincing ‘natural’ dual avoidance.
In each of the Feather’s positionS!, there’s no choice for Black about which wP should go to h7 and so, which mating-square will be guarded.
Add wPg2 to the Feather’s diagram (and move bPg6 to f6). Now there are 2 solutions with one wP respectively completely idle and the other completely artificially placed to cause the black guard of one possible mating-square.
Why ‘artificial’? Well, move wPa4 on Feather’s diagram somewhere else, e.g. to a5, and there are 2 solutions without that ‘guard of one possible mating-square’.
There are 2 pairs of choices, of the square for wK and of the promoted piece. 2×2 good possibilities where the choice from one pair determines the choice from the other pair.
2 RECIPROCALLY USEFUL wPs make 3 pairs of choices, 2x2x2 good possibilities in ONE position… etc.
What means ‘artificial’ and what ‘natural’? Well, the difference comes naturally, so I don’t care about further explaining.