Fairy helpmates with echo diagonal-orthogonal 5

1...Gh7 2.Qg6 Qf5#

1.Qh5 Sb4 2.Qg4 Qf4#

Precise echo diagonal-orthogonal of the model mate - on the line we have wS-x-bK-wQ-bQ-wG. Again the form the set play and solution as in the last time.

1...Gf2 2.Qg4 Gh3 3.Qf3 Re3#

1...Ga4 2.Qb6 Ga6 3.Qb5 Bc4#

This helpmate is indeed and excellent example of D-O echo. Almost everything is perfectly matched and some a bit less analogical points are only due to geometry of the board. Well done!

Subversive unit: it cannot capture, but units of the opposite side under its control don't check normally, but an won king instead.

1.Ke2 ESb3 2.Kf3 Qe3#

1.Ke4 ESb7 2.Qf3 Qd5#

Echo diagonal-orthogonal of the mate. At the first sight subversive pieces seem to be quite flexible and I wonder what is possible to do with them not only in the D-O context...

a) 1.Kb7 Rb2 2.Ka8 Ra2#

b) 1.Ka7 Bc2 2.Ka8 Be4#

Black queen guards potential mating lines, that's why White stops precisely on guard lines and thus cuts them. In the meantime bK enters corner, diggine holes on potential flights.

a) 1...d8B+ 2.Kd2 Bg5+ 3.Ke1 Bd2#

b) 1...d8R+ 2.Kb1 Rb8+ 3.Kf1 Rb1#

And here, with only 3 pieces in the diagram position we see good analogy too. White checking promotion, follow-my-leader repeated twice and a mate using Circe selfguarding and bpg2 as block and cut of line. It is made possible by bK moving twin.

a) 1.Gd8(w) Gd3(b) 2.Gd1(w) Gd7(b)#

b) 1.Gb8(w) Gf4(b) 2.Gh2(w) Gc7(b)#

Whole mating net is constructed, it suffices to check bK. Unusually for Antiandernach chess, the mating move isn't a capturing one. Rather the mate is given over well immobilized black grasshopper making the mating move in a white coat.

1.Gc3 Gd4 2.Ge5 Gf6 3.Gg7 Gh8#

1.Ga3 Ga4 2.Ga5 Ga6 3.Ga7 Ga8#

Hop-hop-hop... reciprocal change of Ga2-Gb2 functions, all 4 corners play some role.

It was suprising to find that this problem reappeared as 8 The Problemist 2004 by Ian Shanahan. Sadly, already even in fairy chess you cannot be always sure of the originality...