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No.1198 |
Original Fairy problems |
Definition: (click to show/hide)
Alphabetic Chess: The squares are considered in the order a1, a2…a8, b1…b8, c1 and so on to h8. At each turn, only the unit standing on the square which comes earliest in this order may move. However check and mate are normal.
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No.1198 Geoff Foster |
Solution: (click to show/hide) |
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white Ke3 Ba8 Rc3 Qd2
black Kb1 Pc4c5e6g6
s#22 (4+5) |
1.Ba8-b7 !
1...Kb1-a1
2.Bb7-a6
2...Ka1-b1
3.Ba6-b5
3...Kb1-a1
4.Bb5-a4
4...Ka1-b1
5.Ba4-b3
5...Kb1-a1
6.Bb3-a2
6...e6-e5 {
}
7.Ba2-b3
7...Ka1-b1
8.Bb3-a4
8...Kb1-a1
9.Ba4-b5
9...Ka1-b1
10.Bb5-a6
10...Kb1-a1
11.Ba6-b7
11...Ka1-b1
12.Bb7-a8
12...Kb1-a1 {
} 13.Ba8-e4
13...g6-g5
14.Rc3-d3
14...Ka1-b1
15.Qd2-c3
15...Kb1-a2
16.Qc3-d4
16...Ka2-b1
17.Rd3-d2 +
17...Kb1-c1 {
} 18.Rd2-c2 +
18...Kc1-b1 19.Rc2-f2 +
19...Kb1-c1
20.Qd4-b2 +
20...Kc1-d1
21.Qb2-c3
21...g5-g4
22.Qc3-d4 +
22...c5*d4 # {
(C+ with Popeye 4.75 using "Option NonTrivial 0 1". That option is not guaranteed
to find all cooks, but I am confident that the problem is sound. (GF))}
The wBa8 does a 12-step ‘staircase’ switchback, with 12.Ba8! being a tempo move. After 12 moves the only change to the diagram position is that the bPe6 is on e5! (Author) |
I remember seeing a s# ending with ABC before, in feenschach – but that may have been a series s# and it may have had some additional condition such as PWC, so this might very well be the first pure s# in ABC. Which is in itself not really important.
ABC seems to give very interesting possibilities to selfmates, as a mating move can be forced without having Black in a very restricted position. You can imagine many free black pieces, perhaps guarding K flights, unable to interfere because of ABC. It is not so in this problem, but note that Black cannot play 22.- Kc1??, Ke1??, or exd4+ because of ABC.
The main idea must be the beautiful B staircase down and then up again, just in order to stalemate the bK so that e5 is forced. The ending after that manoeuvre is perhaps a bit long, but quite efficient, producing an ideal mate. Very good problem!
Nice idea, but please remove “C+”. Test with Popeye was only partial, not full.
As Kjell said, forcing e5 on 6th move is very interesting.