Ajedrecista wrote: ↑Tue Aug 18, 2020 10:42 am

[d]r5kr/pp2q1pp/2pp3B/3n2Q1/3P4/P4R2/6PP/5RK1 w - -

It quickly returns a mate in 13 at shallow depths < 30, which means a mate in 20 from the root position. If I make the move Qg4, then it does not like ... b6 (the proposed black move for the mate in 17) because it shortens white mate. SF prefers ... a6, ... a5 or ... c5, for example. I would look at 12. ... b6, which looks fishy.

Analysis by Cfish 030820 64 POPCNT NUMA:

5.Bh6 d6 6.Qh5 Be6 7.Rae1 N8d7 8.Rxe6 Nf6 9.Qg5 Qc7 10.Rexf6 Nd5 11.R6f3 Qe7 12.Qg4 b6 13.h4 Rb8 14.h5 c5 15.Bg5 Qe2 16.h6 Re8 17.Be3 Qxf1+ 18.Rxf1 g6 19.Qd7 Re7 20.Qc8+ Re8 21.Qxe8#

+- (#17) Depth: 105/34 01:00:19 98077MN

After 12...a6 (instead of ...b6):

Analysis by Cfish 030820 64 POPCNT NUMA:

13.h4 a5 14.h5 a4 15.Bg5 Qe2 16.h6 Re8 17.Be3 Qxg2+ 18.Kxg2 Nxe3+ 19.Rxe3 Re7 20.Qc8+ Re8 21.Qxe8#

+- (#9) Depth: 88/18 00:00:19 568MN

After 12...a5:

Analysis by Cfish 030820 64 POPCNT NUMA:

13.h4 c5 14.h5 b5 15.Bxg7 Ne3 16.Rxe3 Qxe3+ 17.Kh1 Qe8 18.Bh6+ Qg6 19.hxg6 Re8 20.gxh7+ Kxh7 21.Qg7#

+- (#9) Depth: 67/18 00:00:04 99797kN

After 12...c5:

Analysis by Cfish 030820 64 POPCNT NUMA:

13.h4 c4 14.h5 c3 15.Bg5 Qe2 16.h6 Nf4 17.Bxf4 Kf7 18.Bg5+ Ke8 19.hxg7 Qf2+ 20.R1xf2 Rg8 21.Qe6#

+- (#9) Depth: 76/18 00:00:04 115MN