# No.869 (KS)

 No.869, 869.1 Kenneth Solja (Finland) Original Problems, Julia’s Fairies – 2015 (II): July – December →Previous ; →Next ; →List 2015(II) Please send your original fairy problems to: julia@juliasfairies.com

No.869[out of the tournament due to incorrect solutions] by Kenneth Solja – A combination of Back-to-Back and Face-to-Face conditions in a play of fairy neutral pieces! (JV)

No.869.1 by Kenneth Solja – This problem replaces No.869 and shows Back-to-Back alone with the same fairy neutral pieces. (JV)

Definitions:

Moose(M): Moves like a Grasshopper ((0,1)+(1,1)Hopper , but deflects 45° either way on passing over the hurdle. The arrival square is adjacent to the hurdle.

Sparrow(SW): Moves like a Grasshopper ((0,1)+(1,1)Hopper , but deflects 135° either way on passing over the hurdle. The arrival square is adjacent to the hurdle.

Grasshopper(G): Moves along Q-lines over another unit of either color to the square immediately beyond that unit. A capture may be made on arrival, but the hurdle is not affected.

Back-To-Back: When pieces of opposite colors stand back-to-back with each other on the same file (white piece is on the top of black!), they exchange their roles. A pawn on the first rank cannot move. Any piece can make an en passant capture when it has got a role of Pawn by Back-To-Back.

Face-To-Face: When pieces of opposite colors stand face-to-face with each other on the same file (black piece is on the top of white!), they exchange their roles. A pawn on the first rank cannot move. Any piece can make an en passant capture when it has got a role of Pawn by Face-To-Face.

 No.869 Kenneth SoljaFinlandoriginal – 18.08.2015Dedicated to Tadashi Wakashima Solutions: (click to show/hide) white ka1 black kf2 neutral pd2c3a6 ma5 swg5 h#2            3 solutions       (1+1+5)Back-to-Back; Face-to-FaceMoose a5Sparrow g5 1.nPd2-d1=nQ + nQd1-d2 + 2.nSWg5-d3 nSWd3-f1 # 1.Kf2-e1 nSWg5-e2 + 2.Ke1-d1 nPa6-e1=nQ # 1.nPa6-b4 nMa5-c4 2.nPc3-d1=nS nPd2-f1=nM # { (C+ by Popeye 4.69)} Promotions. Fairy promotions. Fairy condition mates (Author) No.869.1 Kenneth SoljaFinlandversion to No.869 – 30.08.2015Dedicated to Tadashi Wakashima Solutions: (click to show/hide) white ka1 black kf3 neutral pa6c3d2g3 ma5 swg5 h#2              3 solutions       (1+1+6)Back-to-BackMoose a5Sparrow g5 1.nPc3-c2 nPd2-d3 2.nPc2-c1=nQ + nQc1-d2 # 1.Kf3-e4 nPg3-g4 2.nPd2-d1=nQ + nQd1*g4 # 1.Kf3-f2 nSWg5-e2 + 2.Kf2-f1 nPa6-f2 # { (C+ by Popeye 4.73)} Promotions. Fairy promotions. Fairy condition mates (Author)

### 10 Responses to No.869 (KS)

1. Julia says:

I wonder why in the 2nd sol. 2.Kd1 is not a selfcheck?
By BTB the nPd2 should check the bKd1 as it gets the K-role. In the 3rd sol. in the analogical pair on the 2nd move the nPd2 gets the role of nSd1 and moves to f1.

• Eric says:

Indeed it seems that the intention of the 2nd solution is not sound.
Besides, the problem seems cooked. Try testing it with Popeye 4.73 and cooks in 1.5 moves will appear, such as:
1…nPd2-d4 2.Kf2-e2 nPa6-e1 #

2. Kenneth Solja says:

Only explonation I have is that Pd2 is black neutral, because black only can promote to the first rank.

• Julia says:

I’ve missed it, in the 3rd solution 2…f1=nM# is also impossible as the pawn can’t promote on the 1st rank on the white move.

3. Kenneth Solja says:

WinChloe found only one solution:
1.ELna5-d3 ELnd3-é1 2.d2-d1=Dn+ Dnd1-é2‡
Can neutral pieces do so much difference?

• Julia says:

Looks like in these moves 1.ELna5-d3 ELnd3-é1 WinChloe ignores the both BTB and FTF. As the both moves should have a pawn’s role, the 1st by FTF and the 2nd by BTB.

I have a feeling that the combination of BTB and FTF is not really defined in the both programs, Popeye and WinChloe.
F.i., I’ve tried in #1 Condition BackToBack, FaceToFace and
Pieces
White Ka2
Black Ka4 Pa5
Neutral Rc5 Bc6
Popeye considers that the side to play can capture the king.
But it is not by BTB! Removing FTF from the conditions saves the bK from the check..

• Georgy Evseev says:

Yes, both second and third solution have an “invalid promotion” on the mating move. Also, it should me marked that in the third solution the second black move is c3-d1 – there is an ambiquity, as two pawns may promote on d1, even though the alternative promotion is illegal.

4. Julia says:

Christian Poisson has confirmed yesterday that BTB and FTF conditions can’t be combined in WinChloe.
I’ll check with Thomas Maeder about Popeye. The solutions have too many errors to consider that the combination is implemented. I believe there’s also lack of definition for such combination (have to check with Tadashi Wakashima?).

5. shankar ram says:

In Raumschach (3D 5x5x5 board), Black starts from top of the board and White from the bottom. So Tadashi has to tell how to apply b2b and f2f here! Maybe top-to-top or bottom-to-bottom..? 😉

6. Kenneth Solja says:

Julia, I will send you another instead of this which is base to the same idea. There is only Back-to-Back -condition.