Meisterwerke

Bl. did not capture. All wh. caps are by Ps: exd, fxe, gxf, hxg & two cross-captures a-b or b-c to get a Pb7 beyond the barrier of bPs. With these constraints, last 13 singles moves are forced:

-1. Rd8-d7+ d7-d6 -2. f5xe6 ep+ (e5-e6+?? bl. retropat) e7-e5 -3. f4-f5+ Kd6-c7 -4. b5xc6 ep+ c7-c5 -5. b4-b5+ Ke6-d6 -6. g5xf6 ep+ f7-f5 -7. g4-g5+ and Bl. avoids retropat.

Solution by Philippe Schnoebelen