Losing Chess: The must-capture rule applies. Kings are non-royal: they can move into check and be captured, pawns may promote to king. As a playable game, the objective is to lose all one’s pieces; a stalemated (i.e. deadlocked) player wins.
No.1253Bernd Gräfrath Germany original – 20.11.2017 Dedicated to François Labelle
Double Homebase, Pronkin-S, Ceriani-Frolkin-K, Switchback of Ke1. For an early example of a Pronkin-S in a Losing Chess proof game with double homebase, see my P1189258 in the PDB. According to Ralf Binnewirtz’s comprehensive collection of Losing Chess problems, the present combination of themes has not been shown before.
I would not have published this problem without the help of François Labelle’s new program “Jacobi”, because testing with Popeye would have taken too long. Now, Jacobi said “C+” after only 5 hours. Hence the dedication: Thank you, François! (Author)
Well done Bernd! Indeed with a so tricky move order, it would have been very risky to publish this PG without Jacobi’s positive verdict!
Paul Rãican
January 20, 2019 22:03
One Pawn can be saved, with reversed colors, I think: 1.c3! e5 2.c4 Ke7 3.c5 Sh6 4.Sf3 e4 5.c6 exf3 6.cxb7 fxg2 7.bxa8=S! gxh1=K! 8.Sxc7 Kxh2 9.Sd5 Ke8 10.Sf4 Kh3 11.Sxh3 Sg8 12.Sg1.
For the moment, I checked only the last 10.5 moves with Jacobi.
Well done Bernd! Indeed with a so tricky move order, it would have been very risky to publish this PG without Jacobi’s positive verdict!
One Pawn can be saved, with reversed colors, I think: 1.c3! e5 2.c4 Ke7 3.c5 Sh6 4.Sf3 e4 5.c6 exf3 6.cxb7 fxg2 7.bxa8=S! gxh1=K! 8.Sxc7 Kxh2 9.Sd5 Ke8 10.Sf4 Kh3 11.Sxh3 Sg8 12.Sg1.
For the moment, I checked only the last 10.5 moves with Jacobi.