nice position

[MikeB]

[d]r3r1k1/1b1nbp1p/1qn1p3/1p1pPp2/p2P4/P2BNN2/1P1Q1BPP/R4RK1 w - -

Bxf5 and Kh1 are good moves, but there is a much better move.

SF, on my machine, sometimes finds it in about 30 seconds, other times are much longer.

[peter]

Hi Michael!

[d]r3r1k1/1b1nbp1p/1qn1p3/1p1pPp2/p2P4/P2BNN2/1P1Q1BPP/R4RK1 w - -

Bxf5 and Kh1 are good moves, but there is a much better move.

SF, on my machine, sometimes finds it in about 30 seconds, other times are much longer.

Started with empty hash (32G) 24 threads of 12x3GHz, no Syzygys, default setting= Analysis Contempt 24 Both:

r3r1k1/1b1nbp1p/1qn1p3/1p1pPp2/p2P4/P2BNN2/1P1Q1BPP/R4RK1 w - - 0 1

Analysis by SugaR Tactical_R x64 POP:

Code: Select all

1.Sxf5 exf5 2.Lxf5 
  +-  (5.11)   Tiefe: 7/7   00:00:00  22kN
...
  +-  (3.70)   Tiefe: 10/11   00:00:00  62kN
1.Sxd5 exd5 2.Lxf5 Sf8 3.Dh6 Lc8 4.Lc2 b4 5.Le3 
  +-  (3.93)   Tiefe: 11/14   00:00:00  96kN
1.Lxf5 Da5 2.Dc2 Kh8 3.Lxh7 Sxd4 4.Sxd4 Tac8 
  +-  (4.14)   Tiefe: 12/17   00:00:00  218kN
1.Lxf5 Scxe5 2.Lxh7+ Kxh7 3.dxe5 Da5 4.Dd4 Kh8 5.Sg4 Tg8 6.Sf6 Lxf6 7.exf6 
  +-  (4.61)   Tiefe: 13/17   00:00:00  345kN
1.Sg4 fxg4 2.Sg5 Teb8 3.Sxh7 Kh8 4.Df4 g3 5.hxg3 
  +-  (6.27)   Tiefe: 14/22   00:00:00  648kN
1.Sxf5 exf5 2.Df4 Sf8 3.Dxf5 Sg6 4.Le3 Lc8 5.Dh5 Le6 6.Sg5 Lxg5 7.Dxg5 Sxd4 8.Kh1 Db8 9.Lxd4 
  +-  (5.19)   Tiefe: 15/23   00:00:00  2726kN
1.Sg4 fxg4 2.Sg5 Sf8 3.Df4 Lxg5 4.Dxg5+ Sg6 5.Le3 Tf8 6.Dh6 Sxd4 7.Tad1 b4 8.Td2 La6 9.Lxa6 Sf5 10.Txf5 Dxe3+ 11.Dxe3 exf5 12.Ld3 f4 13.De2 
  +-  (4.24)   Tiefe: 16/26   00:00:00  4823kN
...
1.Sg4 Tf8 2.Sh6+ Kh8 3.Tae1 b4 4.g4 fxg4 5.Sg5 Lxg5 6.Dxg5 Dd8 7.Dh5 f5 8.exf6 Sxf6 9.Sf7+ Txf7 10.Dxf7 De7 11.Dxe7 Sxe7 12.Txe6 Seg8 13.Lh4 Se4 14.Tf7 Tb8 15.Lg3 
  +-  (4.67)   Tiefe: 24/45   00:00:05  115MN
...
1.Sg4 Tf8 2.Sh6+ Kh8 3.Tae1 Sa5 4.Sg5 Lxg5 5.Dxg5 f6 6.Dh5 fxe5 7.Sf7+ Txf7 8.Dxf7 Dd6 9.dxe5 Tf8 10.exd6 Txf7 11.Txe6 Sf8 12.Ld4+ Kg8 13.Te7 Sc6 14.Txf7 Kxf7 15.Txf5+ Ke6 16.Tf6+ Kd7 17.Le3 Se6 18.Tf7+ Kxd6 19.Txb7 d4 
  +-  (5.45)   Tiefe: 27/42   00:00:19  327MN
...
1.Sg4 Kh8 2.Sh6 Tf8 3.Tae1 Dd8 4.Df4 De8 5.Sxf5 f6 6.Dh6 exf5 7.Lxf5 Df7 8.e6 Dg7 9.Dh5 Tg8 10.g3 Ld6 11.exd7 Taf8 12.Dh3 Lf4 13.Kh1 Lh6 14.Te6 Dxd7 15.Txc6 Dg7 16.Tc5 Te8 17.Le6 Tgf8 18.Te1 Lg5 19.Lf5 Df7 20.Te6 Txe6 21.Lxe6 Dg7 22.Lf5 Lh6 23.Dh5 Lg5 
  +-  (5.42)   Tiefe: 32/56   00:02:27  3105MN
...
1.Sg4 Tf8 2.Sh6+ Kh8 3.g4 Scxe5 4.dxe5 d4 5.gxf5 exf5 6.Lg3 Sc5 7.Sxf5 Tae8 8.e6 Sxd3 9.exf7 Txf7 10.Dxd3 Txf5 11.Dxf5 Tf8 12.Le5+ Kg8 13.Dg4+ Dg6 14.Dxg6+ hxg6 15.Sxd4 Te8 16.Tac1 Ld8 17.Tc5 Lb6 18.Txb5 Lxd4+ 19.Lxd4 La6 20.Ta5 Lxf1 21.Kxf1 Tc8 22.Txa4 Tc2 23.Ta8+ Kf7 24.Ta7+ Ke6 25.Kg1 Kd5 26.Lc3 Kc5 
+-  (4.88)    Tiefe: 34/67   00:05:46  7224MN

And here is CF_EXT (having tactical code from Zerbinati- Forum's RomeoA28 as UCI- option, which works in this position similiar to tactical SugaR's, but is switched off here as default setting, Analysis Contempt off too) after some Forward- Backward:


r3r1k1/1b1nbp1p/1qn1p3/1p1pPp2/p2P4/P2BNN2/1P1Q1BPP/R4RK1 w - - 0 1

Analysis by CF EXT 120319 x64 POP NUMA:

1.Ng4 Rf8 2.Nh6+ Kh8 3.Rae1 Qd8 4.Qf4 b4 5.Nxf5 Ba6 6.Qh6 Rg8 7.Nxe7 Bxd3 8.Nxc6 Qf8 9.Qd2 Bxf1 10.Rxf1 bxa3 11.bxa3 Rc8 12.Nb4 Rg6 13.Be3 Qg7 14.Nd3 Nb6 15.Nh4 Nc4 16.Nxg6+ Qxg6 17.Qf2 Nxa3 18.Nf4 Qg4 19.Nh5 Qg6 20.Qxf7 Nc4 21.Qe7 Rg8 22.Nf4 Qg7 23.Qxg7+ Rxg7 24.Bf2 a3
+- (4.59) Depth: 37/65 00:08:42 10369MN

And after 1.Ng4 fxg4 instead of ...Rf8:

r3r1k1/1b1nbp1p/1qn1p3/1p1pP3/p2P2p1/P2B1N2/1P1Q1BPP/R4RK1 w - - 0 1

Analysis by CF EXT 120319 x64 POP NUMA:

2.Qh6 Nf8 3.Be3 Qc7 4.Bg5 Nxe5 5.Nxe5 f5 6.Nxg4 Bxg5 7.Qxg5+ Kh8 8.Nf6 Ng6 9.Nxe8 Rxe8 10.Qf6+ Qg7 11.Qxg7+ Kxg7 12.Bxb5 Rb8 13.Bxa4 Ba6 14.Rf2 Kf6 15.Re1 Bc4 16.Re3 h5 17.b3 Ba6 18.b4 h4 19.Bd7 Nf8 20.Bc6 Rb6 21.Ba4 Rb8 22.Rc2 Bc4 23.Bb3 f4 24.Rf2 Bxb3 25.Rxb3 e5 26.dxe5+ Kxe5 27.Re2+ Kd6 28.Rh3 Ng6 29.Rd2 Rd8 30.a4
+- (4.65) Depth: 36/68 00:00:52 1103MN