Circe problems without captures 1

1.Bb1! th. 2.Qc5#
1...Kc4 2.g8B#
1...Kd5 2.g8Q#
1...Ke5 2.Qd6#
1...Ke3 2.Qf2#
1...Kc3 2.Qb4#

The key provides flight, thus Black has five of them after the key. Two variations with promotions are separated by possible capture and need to Circe self-protection. In threat and three other variations the mate is given by Circe self-protected queen.

1.Rc1! th. 2.Sb3#
1...Rb3 2.Qd3#
1...Bb3 2.Sc4#
1...b3 2.Bb4#
(1...Ra3 2.Qd3#, 1...Re3 2.Qxc2(c7)#, Qd3#, 1...bxa5(Sg1) 2.Sf3#)

The rook vacates rebirth square of the white knight, allowing threat with knight's Circe self-protection. However Black can be there the first. But any of three pieces moved to b3 allows mate on its departure square with good use of Circe self-protection again. (Compare this and the fifth problem in this file by S. Trommler.)

1.Sa7! zz
1...Qa4 2.Ka2#
1...Qb4 2.Kb2#
1...Qc4 2.Kc2#
1...Qc5 2.Ka1#
1...Qb6 2.Kc1#

Five specific variations. Black queen of course cannot capture and all her moves block, allowing firing white royal battery with possible unguard of just blocked square.

1.Ba8! th. 2.c8Q#
1...Rf2 2.Bh8 th. 3.c8Q#
2...Rd2 3.c8R#

Specific play for Mars Circe starts by wB blocking Circe square of bR. bK cannot move and thus bR has to organize defence. Switch of Circe square colour motivates another corner-to-corner move. Black rook can defend by attacking d1, but at the same time it unguards h1-f1 line.

1.b6! th. 2.Sc7+ Kc3 3.Sb5#
1...Rb1 2.Se3+ Kc3 3.Sd1#
1...Bb1 2.S5b4+ Kc3 3.Sa2#

Standard Siers battery is enriched by Circe motivation behind. In the threat wS cannot be captured by bS due to the selfcheck from b1. That is why Black goes to b1 by two pieces with possible selfcheck by White, but White fires the battery nevertheless, using the newly vacated squares. (Compare this and the second problem in this file by A. Tungler.)

1.f8Q! Ka2 2.b8R+ Kb2 3.g8S B~ 4.h8B#

Another promotion exercise in Mars Circe. Queen promotion confines bK to a very tight cage, then White sets up full quartet of pieces needed for mate.

There was one pawn too many on the board, thanks to Lennart for pointing that.

1.Rh3! Kg2 2.Sg3 Kh1 3.a4 Kg2 4.a5 Kh1 5.a6 Kg2 6.a7 Kh1 7.Rh2+ Kg2 8.a8B#

First two white moves prepare cage for bK which then just oscillates between h1 and g2. Then White can do (almost) whatever he wants. E.g. bishop promotion.