No. 223, February 2007
13283 - Alexander Yarosh Die Schwalbe 223, February 2007
7+14. Add a white and a black pawn, then retract one white move for a #2
[2Nnk2r/bQp2prb/1p4p1/8/3pp3/nP2P3/1q1P1PK1/8]
13284 - Paul Raican Die Schwalbe 223, February 2007
12+15. Proof game in 23.5 moves
[rn5N/ppppnBp1/4pb2/4rpk1/P7/3K2Pq/1PPPP3/1NB3Nn]
13285 - Jorge Lois, Roberto Osario Die Schwalbe 223, February 2007
14+15. Proof game in 26.5 moves
[rn2qkbr/4pp1n/1p4p1/bp1p2p1/2PQP3/1P3N2/2PN1PP1/2BRRBK1]
Editor's note: The problem was incorrectly published as "PG in 25.5 moves".
13286 - Alexander Yarosh Die Schwalbe 223, February 2007
4+8. Add 9 pieces for an Illegal Cluster
[8/pppppppp/8/8/1P6/8/P2P3P/8]
13287 - Günther Weeth, Klaus Wenda Die Schwalbe 223, February 2007
3+8. Retract 6 moves, then mate in 1 move, Proca retractor, Anticirce
[2nr4/8/R7/8/8/kp1pp3/8/qrR1K3]
13288 - Günther Weeth Die Schwalbe 223, February 2007
9+13. Retract 21 moves, then mate in 1 move (Proca retractor, Anticirce)
[1N3N2/6p1/2b1PPqp/2p3p1/kPn5/P1bpK2P/P1p5/2r2n2]