No. 222, December 2006
13232 - Dmitri Baibikov Die Schwalbe 222, December 2006
2+2. Add 2 wRR, wB, wS and 8 bP for an illegal cluster
[n1N1k2K/8/8/8/8/8/8/8]
13233 - Emiliano F. Ruth Die Schwalbe 222, December 2006
(Correction of 13078)
5+9. Retract 3 moves, then mate in 1 move (Proca retractor, AntiCirce)
[1rb5/4B3/2k4p/4R2p/2K4p/1p5p/1P5p/4R3]
13234 - Günther Weeth Die Schwalbe 222, December 2006
1+6. Retract 6 moves, then mate in 1 move (Proca retractor, Anticirce)
[2n2n2/4p3/1pp5/8/7k/8/8/4K3]
13235 - Wolfgang Dittmann Die Schwalbe 222, December 2006
(Correction of 13079)
12+9. Retract 15 moves, then mate in 1 move (Proca retractor, Anticirce)
[1k1n4/1Pb2P2/1P1p1N1p/B6b/5P1P/4P1Kn/p3PP1r/5B2]
13236 - Michael Grushko Die Schwalbe 222, December 2006
1+1+1. White and black retract 1 move for h=1. Neutral bishop e5 (Circe Parrain, Checkless chess)
[8/8/8/4B3/4K3/7k/8/8]
13237 - Gerald Irsigler Die Schwalbe 222, December 2006
How many squares can you mark at most on a chess board so that every possible position with pieces on those squares (including wK and bK) is legal?
(e.g.: mark e1 g2 h1 isn't valid, since wKe1, wBh1 wKg2 isn't legal. e1 g3 h1 is valid though)