Tries in fairy problems 2

1.Qe7? th. 2.Re1 fxe1Q#
1...Ba3! 2.Qxa3#

1.Qd8? th. 2.Re1 fxe1Q#
1...Sa8! 2.axb8Q#

1.Qh5? th. 2.Re1 fxe1Q#
1...e4! 2.Ra1#

1.Qh6! th. 2.Re1 fxe1Q#

White wants to hide wQ somewhere to allow usual mate by queen promotion. The choice must be done very carefully. Despite innocent look, there are 3 mates on the a-file, two of them with active pin wittily activated from halfpin configurations.

1.Rd3? th. 2.Rg3 th. 3.Rg1 f,hxg1Q#
1...b5! 2.Rg3 b4 3.Sb5#

1.Rd4? th. 2.Rg4 th. 3.Rg1 f,hxg1Q#
1...Kxb3! 2.Rg4 Ra3 3.Sd2#

1.Rd5? th. 2.Rg5 th. 3.Rg1 f,hxg1Q#
1...Kb4! 2.Rg5 Ra3 3.Rb5#

1.Rd6? th. 2.Rg6 th. 3.Rg1 f,hxg1Q#
1...Kb4! 2.Rg6 Ka5 3.Bc3#

1.Rd8! th. 2.Rg8 th. 3.Rg1 f,hxg1Q#

Excellent reflex strategy in the open meredith position. Black defends by taking into account the way of White's attack and the fact that the option rook stays on the same row in the second move, thus allowing twomove combination.

1.c8Q? zz
1...Ke4! 2.Qc6#

1.c8S? zz
1...Kc6! 2.Se7#

1.c8R? zz
1...Ke6! 2.Rc6#

1.c8B? zz
1...Kc4! 2.Be6#

1.c8G! zz
1...K~ 2.Bh2 Sf2#

To force Black to mate White needs to attain two elements. Unpin bK - it is enough to wait for Black to move the king. And open line of blocking wB - this must be done by promotion of wP. The promoted piece however has to be chosen carefully - otherwise Black can force him to mate by appropriate move in the star shape.

1.c8S,R? th. 2.Bh2 cxb1Q#
1...Rd6!

1.c8B? th. 2.Bh2, Bh3 cxb1Q#
1...gxh6(Sg1)! 2.Sf3#

1.cxd8Q,B(Rh8)? th. 2.Bh2 cxb1Q#
1...Rxh7(h2)! 2.Bg3#

1.cxd8S(Rh8)? th. 2.Bh2 cxb1Q#
1...Rxd8(Sg1)! 2.Sf3#

1.cxd8R! th. 2.Bh2 cxb1Q#
1...Rxd8(Ra1) 2.Kxb2(Bf8) Bxa3(a2)#
1...Rxh7(h2) 2.~ cxb1Q#

And the Bb8-Pc7 configuration appears once more. This time the move of bishop to h2 is motivated by Circe need to close h1-h4 line of the rook captured in the mating move. The first pair of tries 1.c8S,R? shows it is also necessary to cope with possible defence by Rd8 closing line of bishop. Next try adds the second threat, but also guards g4. Therefore White tries to capture the rook, but it still can play its role from h8 again, allowing bishop or knight mate.

1.Sxf4? th. 2.e4 Sxf4#
1...Qa7! 2.c8S#

1.Sdf6!? th. 2.exf4 Sxf4#
1...Se5! 2.Bf8#

1.Se7!? th. 2.exf4 Sxf4#
1...dxe6! 2.Rd8#

1.Sc3!? th. 2.exf4 Sxf4#
1...dxc6! 2.Rd1#

1.Sb6! th. 2.exf4 Sxf4#
1...f3 2.e4 Sf4#
1...Rxe3 2.b3 Rh2#
1...g2 2.Rh1 gxh1Q#
(1...fxe3 2.~ Sxf4#)

The plan of White is simple. Pair of units Pe3 and Sd5 guard blocked square f4. It is thus enough to move with one unit away and with the other to f4. Jump of knight to f4 allows mate by knight promotion, using 4 line guards Qa5-c7, Rc1-c6, Re8-e6, Bg7-e5. White corrections then try to cut these lines, but Black still manages to block unguarded squares and force three new mates. The last possibility is the right one...

1.g8Q? th. 2.d3 Bxc3#
1...Kh4! Qh7#

1.g8B? th. 2.d3 Bxc3#
1...K3g2! 2.Bd5#

1.g8S? th. 2.d3 Bxc3#
1...Bh4!

1.g8R! th. 2.d3 Bxc3#
1...Bh4 2.Bf6 Bxf6#
1...Bg3 2.Be5 Bxe5#
1...Bf2 2.Bd4 Bxd4#
(1...Bxd2 2.~)

Good use of unusual fairy condition (do not confuse it with siamese units), the black manages twice to force the mate and once to move to square attacked by promoted knight. Especially the economy is very good.

1.Ke1? (2.Sxf4) Bxb5! (Qe4?) 2.Sg3#
1.Kf1? (2.Sxf4) Qe4! (Bxb5?) 2.Sd4#

1.Rg2! (2.Rg3 ~ 3.Bxa2/Rd3 Qxe2#)
1...Bd6 2.Ke1! ~ 3.Sxf4 Q/Rxb1# (2.Kf1? Qe4! 3.Sd4#)
1...Be5 2.Kf1! ~ 3.Sxf4 Q/Rxb1# (2.Ke1? Bxb5! 3.Sg3#)
1...Bxb5 2.Rxf4+ B/gxf4 3.Bxa2 Qxe2#
(1...Ke4 2.Kf1 ~ 3.Sd4/Sxf4 Rxb1#)

White wants to unpin Se2 and move him away to force mate on the 1st row. However he must not hurry as too quick unpins allow Black to force the mate - with anti-dual effects. Defences then neutralize mates, by anticipatory closing line of wQ and by guarding the potential mating square.