Hi Walter!
Very nice one again!
BTW, it seems to be a mate in 37 or a few moves less. Last three aren't to be kept in 32G hash easily anymore, but here's Backward- output at the position after 3...Rd4+:
1N6/2pp1P2/8/p3k3/1pKr1N2/5P1P/8/8 w - - 0 1
Analysis by asmFishWCP_2018-10-28_popcnt:
4.Kb3 Txf4 5.Sxd7+ Kd5 6.f8D Txf8 7.Sxf8 c5 8.Kb2 c4 9.Sd7 c3+ 10.Kc2 Kc6 11.Sf6 Kc5 12.Kd3 a4 13.Se4+ Kc6 14.Sxc3 a3 15.h4 bxc3 16.Kxc3 a2 17.Kb2 a1D+ 18.Kxa1 Kd5 19.h5 Ke6 20.Kb1 Kf6 21.f4 Kf5 22.Kb2 Ke6 23.h6 Kf7 24.f5 Kf6 25.Kc3 Kf7 26.Kc4 Kf6 27.Kd4 Kf7 28.Ke5 Kf8 29.f6 Kg8 30.Kf5 Kf8 31.h7 Ke8 32.f7+ Kxf7 33.h8D Ke7 34.Dd4 Kf7 35.Dd7+ Kf8 36.Kf6
+- (#34) Tiefe: 51/65 00:03:21 12554MN
Of course of no meaning at all for a study, that isn't a mate in x- problem, just for even more horror- fun.
Happy Halloween!
Edit: Yet couldn't resist to finish the Backward anyhow:
1N6/2pp4/3k1P2/p7/1pK1P3/5P1P/3r2N1/8 w - - 0 1
Analysis by asmFishWCP_2018-10-28_popcnt:
1.e5+ Ke6 2.Sf4+ Kxe5 3.f7 Td4+ 4.Kb3 Txf4 5.Sxd7+ Kd5 6.f8D Txf8 7.Sxf8 c5 8.Sd7 c4+ 9.Kb2 c3+ 10.Kc2 Kc6 11.Sf6 Kc5 12.Kd3 a4 13.Se4+ Kc6 14.Kc2 a3 15.Kb3 Kd5 16.Kxb4 c2 17.Sc3+ Ke5 18.Sa2 Kf6 19.h4 Kg6 20.f4 Kg7 21.Kxa3 Kg6 22.Sc1 Kh5 23.f5 Kh6 24.Kb3 Kh5 25.Kxc2 Kh6 26.Kc3 Kg7 27.h5 Kg8 28.Kc4 Kh7 29.f6 Kg8 30.h6 Kf7 31.h7 Kxf6 32.h8D+ Kf5 33.Kd5 Kf4 34.Df6+ Kg4 35.Ke4 Kg3 36.Se2+ Kg2 37.Df3+ Kh2 38.Df2+ Kh3 39.Dg3#
+- (#39) Tiefe: 56/78 00:02:08 6225MN
Still would lay my bets rather on #37, any other findings from other mate- solvers?
Will let it run a little longer with full hash and will come back later maybe.