No.905 (GF)

 No.905 Geoff Foster (Australia) Original Problems, Julia’s Fairies – 2015 (II): July – December    →Previous ; →Next ; →List 2015(II) Please send your original fairy problems to: julia@juliasfairies.com

No.905 by Geoff Foster – A very interesting difference in promotions in a strict and Relaxed Symmetry Anti-Circe! (JV)

Definitions:

Anti Take & Make: Every capture (“take”) must be complemented by a further step (“make” which is not a capture) by the captured piece (Kings excluded), which must move from its square of vanish (according to the wishes of the capturing side in case of options). The capture is forbidden if the captured unit has no possible moves. Promotions at the end of the “make” element are normal.

Symmetry Anti-Circe: As Anti-Circe except that the rebirth square for the capturing unit is that which is symmetrical in Symmetry Circe.

Relaxed Symmetry Anti-Circe: ‘Relaxed’, which is the opposite of ‘Strict’, means that a capture can still take place even if the rebirth square is occupied (in relaxed Anti-Circe, if the rebirth square is occupied then the capturing unit disappears from the board). (implemented in the latest version of Popeye, 4.73)

Anti-Circe: After a capture the capturing piece (Ks included) must immediately be removed to its game array square (necessarily vacant, else the capture is illegal). R, B & S go to the square of the same colour as the capture; Ps stay on the file of capture; fairy pieces go to the promotion square of the file of capture.

 No.905 Geoff FosterAustraliaoriginal – 27.09.2015 Solutions: (click to show/hide) White kc7 Black kg4 Neutral pd7f2 h#2.5                                  (1+1+2)Anti-Take&MakeSymmetry Anti-Circeb) Symmetry Anti-Circe→Relaxed Symmetry Anti-Circe a) 1...nPd7-d8=nQ 2.nPf2-f1=nQ + nQd8-h4 + 3.Kg4*h4[bKh4->a5][+nQh3] { } nQf1*h3[nQh3->a6][+nQa3] # b) 1...nPd7-d8=nR 2.nPf2-f1=nR nRf1-f4 + 3.Kg4*f4[bKf4->c5][+nRd4] { } nRd8*d4[nRd4->e5][+nRc4] # { (C+ by Popeye 4.73)} Two promotions to nQ become two promotions to nR! In (a), 1...nPd8=nQ is legal because the nPf2 protects the wK from check. The solution of (b) will not work in (a) because of 4.nRf4! or 4.Kd4+! (Author)