# No.1198 (GF)

 No.1198 Geoff Foster (Australia) Original Fairy problems JF – 2017(I): January – June

Definition: (click to show/hide)

 No.1198 Geoff Foster Australia original – 21.03.2017 Solution: (click to show/hide) white Ke3 Ba8 Rc3 Qd2 black Kb1 Pc4c5e6g6 s#22                                             (4+5) Alphabetic Chess 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))} It might be the first time that ABC Chess has been used in a selfmate (there are no examples in WinChloe)! 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)

### 3 Responses to No.1198 (GF)

1. Kjell Widlert says:

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!

2. Nice idea, but please remove “C+”. Test with Popeye was only partial, not full.

3. S. K. Balasubramanian says:

As Kjell said, forcing e5 on 6th move is very interesting.