Black hole

[lech]

Welcome to the wonderful world of selective search! The holy grail of computer chess is knowing which moves to prune and which moves not to prune so if you can figure that out, please let us know

It looks like that I made it in endgames (material <= 4R + 2B +Ps).
Additionally first tests show that it can be stronger than source (Stockfish 1.8).
Will the name "Sting" good ?
Of course, I am very happy that fast engines can solve my positions. Thanks all for tests.

[Vinvin]

I like the speed difference
An antique P-IV vs a recent 12 cores, the speed ratio is about 200x

Code: Select all

Houdini 1.5ab-16 x64 [12 thr 14 spl] (4096 MB)
 33/57	 2:15 	-2.24 	1...Bg3+ 2.Kd7 Rg4 3.Nc6 Bd6 4.Bb3 Rg5 (4.086.089.061) 30114...

Code: Select all

Houdini_15a_w32 P-IV, 3GHz, 2 threads:
 31/55	1:10:19	2.973.738 488	704.000	+2,19	Bh4f2 Ba4b3 Bf2c5 Nd8c6 Rg8g2 Kc7d7 Rg2d2+ Kd7c8 Rd2h2 Kc8b7 Rh2h5 Kb7a6 Bc5d6 Ka6b6 Rh5f5 Nc6d8 Rf5g5 Nd8c6 Rg5h5 Kb6a6 Rh5f5 Ka6b6 Rf5g5 Kb6a6 Rg5h5 Ka6b6

Only about 50 times faster, when measured in nodes per second:

36 449 543.1 / 704 844.392 = 51.7128937.

I measured the time :
P-IV : 70 min to get depth 31
12 Cores : 2.25 min to get depth 33

Ratio : 31.11

2 plies deeper : I count factor 6.25 (2.5 ^ 2)

31.11*6.25 = 194


NPS don't the take account of Hash memory.

[Karol Majewski]

I made some analysis of the following position:

[D]3N2r1/2K1p3/4Pk2/8/Bp5b/8/2P5/8 b - - 0 1

and my conclusion is: mate in 28.

Here's a sample line:

1... Bg3+ 2. Kd7 Rxd8+ 3. Kxd8 Kxe6 4. Ke8 Kd6 5. Kf7 e5 6. Bb5 e4 7. Kg6 Kc5 8. Ba6 Kd4 9. Kf5 e3 10. Kg4 Kc3 11. Kf3 Kd2 12. Bc4 Bf2 13. Bb5 Kxc2 14. Ke2 b3 15. Ba4 Kb2 16. Kd1 Ka2 17. Be8 b2 18. Bg6 b1=Q+ 19. Bxb1+ Kxb1 20. Ke2 Kc2 21. Kf3 Kd3 22. Kf4 e2 23. Ke5 e1=Q+ 24. Kd5 Qe7 25. Kc6 Qd8 26. Kb5 Qb6+ 27. Ka4 Kc2 28. Ka3 Qb3#

[lech]

It is only a part of Holy Grail (first step).
There are only prohibited : null move pruning, reduction
and opened wide futility window
for such sensitive positions (rather theirs kinds).
I found some common features of these positions and possible next ones which can disappear in black hole. Of course it needs a precious code to avoid a wide gate.


[d] 3N2r1/2K1p3/4Pk2/8/Bp5b/8/2P5/8 b - - 0 1

Code: Select all

Sting beta:
   1	00:00	          54	216	+3,23	Bh4f2
   2	00:00	         137	548	+2,98	Bh4f2 Ba4b5
   2	00:00	         179	716	+3,39	Bh4g3+ Kc7d7 Bg3f4
   3	00:00	         447	1.680	+2,78	Bh4g3+ Kc7d7 Bg3f4 Nd8c6
   3	00:00	         695	2.612	+2,90	Bh4g5 Nd8c6 Rg8a8
   4	00:00	       1.191	4.477	+2,70	Bh4g5 Nd8c6 Kf6f5 Kc7d7
   4	00:00	       1.366	5.135	+2,94	Bh4g3+ Kc7d7 Bg3f4 Nd8c6 Rg8a8
   5	00:00	       2.679	9.533	+2,78	Bh4g3+ Kc7d7 Rg8g5 Ba4c6 Rg5c5 Bc6e4 Rc5c7+ Kd7e8
   5	00:00	       3.921	13.202	+3,03	Rg8g4 Ba4b5 Bh4g3+ Kc7b6 Bg3f2+ Kb6c7 Kf6e5
   6-	00:00	       4.762	16.033	+2,90	Rg8g4 Ba4b5
   6	00:00	       6.490	20.801	+2,94	Rg8g4 Ba4b5 Bh4g3+ Kc7b6 Bg3f4 Kb6c5 Rg4g8
   7-	00:00	       8.820	26.890	+2,82	Rg8g4 Ba4b3
   7-	00:00	      14.595	42.427	+2,70	Rg8g4 Ba4b3
   7	00:00	      21.453	57.208	+2,70	Rg8g4 Ba4b3 Bh4g3+ Kc7b6 Bg3d6 Nd8c6 Rg4g5 Bb3a2 Rg5g2 Ba2b3
   8	00:00	      22.317	59.512	+2,70	Rg8g4 Ba4b3 Bh4g3+ Kc7b6 Bg3d6 Nd8c6 Rg4g5 Bb3a2 Rg5g2 Ba2b3
   9	00:00	      33.895	83.485	+2,62	Rg8g4 Ba4b3 Bh4g3+ Kc7b6 Bg3d6 Nd8c6 Rg4g5 Bb3a2 Rg5g2 Ba2b3 Rg2h2 Kb6b5 Rh2h5+ Kb5b6
   9+	00:00	      36.388	86.227	+2,82	Bh4g3+ Kc7d7
   9	00:00	      38.418	87.712	+2,82	Bh4g3+ Kc7d7 Bg3d6 Ba4b5 Rg8g5 Bb5c6 Rg5a5 Bc6e4 Ra5a7+ Kd7c6 Bd6c7 Nd8b7
  10-	00:00	      58.144	120.132	+2,70	Bh4g3+ Kc7d7
  10	00:00	      89.192	154.311	+2,74	Bh4g3+ Kc7d7 Bg3d6 Ba4c6 Bd6c5 Bc6d5 Rg8g5 Bd5b3 Rg5g2 Nd8c6 Rg2d2+ Kd7e8 Bc5d6 Ke8d8
  11	00:00	     138.545	192.691	+2,82	Bh4g3+ Kc7d7 Bg3d6 Ba4c6 Bd6c5 Bc6d5 Rg8g5 Bd5b3 Rg5g2 Nd8c6 Rg2d2+ Kd7e8 Bc5d6 Ke8d8
  12	00:00	     146.895	195.860	+2,82	Bh4g3+ Kc7d7 Bg3d6 Ba4c6 Bd6c5 Bc6d5 Rg8g5 Bd5b3 Rg5g2 Nd8c6 Rg2d2+ Kd7e8 Bc5d6 Ke8d8
  13	00:00	     161.733	207.084	+2,82	Bh4g3+ Kc7d7 Bg3d6 Ba4c6 Bd6c5 Bc6d5 Rg8g5 Bd5b3 Rg5g2 Nd8c6 Rg2d2+ Kd7e8 Bc5d6 Ke8d8
  14+	00:01	     260.954	249.239	+2,90	Bh4g3+ Kc7d7
  14	00:01	     285.421	257.136	+2,94	Bh4g3+ Kc7d7 Rg8g4 Nd8c6 Bg3d6 Ba4b3 Rg4g2 Kd7e8 Rg2d2 Ke8d8 Bd6c5+ Kd8c7 Kf6f5 Bb3c4 Kf5e4 Bc4b3
  15-	00:01	     346.973	267.519	+2,82	Bh4g3+ Kc7d7
  15	00:01	     412.346	280.698	+2,82	Bh4g3+ Kc7d7 Rg8g4 Nd8c6 Bg3d6 Ba4b3 Rg4g2 Nc6d4 Bd6c5 Nd4c6 Rg2d2+ Kd7c7 Rd2h2 Kc7d7 Rh2g2 Kd7d8 Bc5b6+ Kd8d7 Rg2d2+ Kd7e8 Bb6c5
  16	00:01	     454.256	284.800	+2,82	Bh4g3+ Kc7d7 Rg8g4 Nd8c6 Bg3d6 Ba4b3 Rg4g2 Nc6d4 Bd6c5 Nd4c6 Rg2d2+ Kd7c7 Rd2h2 Kc7d7 Rh2g2 Kd7c7 Kf6f5 Bb3c4 Rg2d2 Bc4b3
  17	00:02	     693.334	316.735	+2,82	Bh4g3+ Kc7d7 Rg8g4 Nd8c6 Bg3d6 Ba4b3 Rg4g2 Nc6d4 Bd6c5 Nd4c6 Rg2d2+ Kd7c7 Rd2h2 Kc7d7 Rh2g2 Kd7c7
  18-	00:02	     961.637	341.733	+2,74	Bh4g3+ Kc7d7
  18	00:04	   1.628.612	369.383	+2,74	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6d4 Bd6c5 Nd4f3 Bc5f2 Bb3c4 Bf2e3 Bc4b3 Rh8h1 Bb3c4 Rh1h5 Bc4b3 Be3f4 Bb3c4 Rh5h3
  19-	00:06	   2.578.600	383.549	+2,66	Bh4g3+ Kc7d7
  19	00:14	   5.125.875	366.290	+2,66	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6d8 Rh8h5 Kd7c6 Bd6g3 Kc6b7 Rh5b5+ Kb7c6 Rb5g5 Kc6d7
  20	00:20	   7.398.817	357.949	+2,66	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6d8 Rh8h5 Kd7c6 Bd6g3 Kc6b7 Rh5b5+ Kb7c6 Rb5g5 Kc6d7
  21	00:25	   9.383.621	370.923	+2,62	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6a5 Bd6c5 Na5c6 Rh8h2 Nc6d8 Rh2h5 Kd7c7 Kf6f5 Kc7d7 Rh5g5 Kd7c6
  22	00:33	  12.842.930	379.743	+2,62	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6a5 Bd6c5 Na5c6 Rh8h2 Nc6d8 Rh2h5 Kd7c7 Kf6f5 Kc7d7 Rh5g5 Kd7c6 Kf5f6
  23	00:46	  17.336.686	374.717	+2,62	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6a5 Bd6c5 Na5c6 Rh8h2 Nc6d8 Rh2h5 Kd7c7 Kf6f5 Kc7d7 Rh5g5 Nd8c6 Kf5f6 Nc6d8 Rg5g2
  24	01:17	  30.649.638	395.765	+2,62	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6a5 Bd6c5 Na5c6 Rh8h2 Nc6d8 Rh2h5 Kd7c7 Kf6f5 Kc7d7 Rh5g5 Nd8c6 Kf5f6 Nc6d8 Rg5g2 Kd7c6
  25	01:32	  36.784.595	396.394	+2,62	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6a5 Bd6c5 Na5c6 Rh8h2 Nc6d8 Rh2h5 Kd7c7 Kf6f5 Kc7d7 Rh5g5 Nd8c6 Kf5f6
  26	02:11	  51.148.321	388.278	+2,62	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6a5 Bd6c5 Na5c6 Rh8h2 Nc6d8 Rh2h5 Kd7c7 Kf6f5 Kc7d7 Rh5g5 Nd8c6 Kf5f6
  27	03:13	  76.570.048	395.854	+2,62	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6a5 Bd6c5 Na5c6 Rh8h2 Nc6d8 Rh2h5 Kd7c7 Kf6f5 Kc7d7 Rh5g5 Nd8c6 Kf5f6
  28	04:03	  95.111.990	390.801	+2,62	Bh4g3+ Kc7d7 Bg3f4 Ba4b3 Rg8h8 Nd8c6 Bf4d6 Nc6a5 Bd6c5 Na5c6 Rh8h2 Nc6d8 Rh2h5 Kd7c7 Kf6f5 Kc7d7 Rh5g5 Nd8c6 Kf5f6
  29+	05:25	 120.952.380	371.070	+2,70	Bh4g3+ Kc7d7
  29+	05:39	 125.445.010	369.647	+2,78	Bh4g3+ Kc7d7
  29+	06:26	 141.685.474	366.795	+3,91	Bh4g3+ Kc7d7
  29+	06:44	 148.162.309	366.312	+5,21	Bh4g3+ Kc7c8

Sting (beta) needs 5 minutes to do it on PIV 3 GHz, 2 threads, primitive compilation.

[lech]

[d] 7k/6rB/6P1/7q/2p5/2B5/3P4/5K2 b - - 0 1

Code: Select all

Sting (beta):
   1	00:00	          87	348	+9,33	Qh5d5
   2	00:00	         165	660	+9,21	Qh5d5 Kf1e2 Qd5e4+ Ke2f2
   3	00:00	         576	2.165	+9,09	Qh5d5 Bc3xg7+ Kh8xg7 Kf1e2 Qd5d3+ Ke2e1
   3	00:00	         723	2.718	+9,21	Qh5f3+ Kf1e1 Qf3g2 Bc3xg7+ Kh8xg7
   4	00:00	       1.163	4.372	+9,21	Qh5f3+ Kf1e1 Qf3g2 Bc3xg7+ Kh8xg7 Ke1d1
   5	00:00	       1.911	7.184	+9,25	Qh5f3+ Kf1e1 Qf3g2 Bc3xg7+ Kh8xg7 Ke1d1 Qg2f2
   6-	00:00	       3.470	12.304	+9,17	Qh5f3+ Kf1e1
   6+	00:00	       4.898	16.491	+9,33	Qh5f3+ Kf1e1
   6	00:00	       5.044	16.983	+9,33	Qh5f3+ Kf1e1 Qf3g2 Bc3xg7+ Kh8xg7 Ke1d1 Qg2e4 Kd1c1
   7-	00:00	       7.427	23.728	+9,21	Qh5f3+ Kf1e1
   7-	00:00	       9.110	29.105	+9,09	Qh5f3+ Kf1e1
   7	00:00	      10.357	31.480	+9,13	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1d1 Qd5g2 Kd1c2
   8	00:00	      16.251	47.241	+8,92	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1d1 Qd5g2 Bc3xg7+ Kh8xg7 Kd1c2 Qg2g3 Kc2b2 Qg3b3+ Kb2c1 Qb3d3 Kc1d1 Qd3e4 Kd1c1
   9	00:00	      18.876	54.872	+8,92	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1d1 Qd5g2 Bc3xg7+ Kh8xg7 Kd1c2 Qg2g3 Kc2b2 Qg3b3+ Kb2c1 Qb3d3 Kc1d1 Qd3e4 Kd1c1
  10	00:00	      23.831	66.197	+8,92	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1d1 Qd5g2 Bc3xg7+ Kh8xg7 Kd1c2 Qg2g3 Kc2b2
  11	00:00	      31.355	80.191	+8,92	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1d1 Qd5g2 Kd1c2
  12+	00:00	      34.793	88.984	+9,01	Qh5f3+ Kf1e1
  12+	00:00	      35.325	86.793	+9,09	Qh5f3+ Kf1e1
  12	00:00	      37.887	93.088	+9,17	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1d1 Qd5g2 Kd1c2 Qg2f3
  13	00:00	      51.084	116.630	+9,13	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1
  14	00:00	      66.023	140.773	+9,13	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1c2 Qd5f3
  15	00:00	      97.738	183.718	+9,13	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1c2 Qd5f3
  16	00:00	     130.904	220.377	+9,13	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1c2 Qd5f3
  17	00:00	     184.727	262.396	+9,13	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1c2 Qd5f3
  18-	00:00	     316.553	337.476	+9,05	Qh5f3+ Kf1e1
  18	00:01	     353.622	348.053	+9,09	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1c2 Qd5f3
  19	00:01	     522.796	403.080	+9,09	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4d5 Kc1c2 Qd5f3
  20-	00:01	     891.432	471.407	+9,01	Qh5f3+ Kf1e1
  20+	00:02	     997.099	479.605	+9,17	Qh5f3+ Kf1e1
  20	00:02	   1.071.568	486.192	+9,05	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4f3 Kc1c2 Qf3g3
  21	00:03	   1.550.206	519.331	+9,09	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4f3 Kc1c2 Qf3g3
  22+	00:03	   1.795.317	526.949	+9,17	Qh5f3+ Kf1e1
  22	00:03	   2.022.408	543.804	+9,09	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4f3 Kc1c2 Qf3g3
  23	00:04	   2.550.337	558.916	+9,09	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4f3 Kc1c2 Qf3g3
  24	00:05	   3.369.965	582.837	+9,09	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4f3 Kc1c2 Qf3g3
  25	00:09	   5.718.591	604.885	+9,09	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4f3 Kc1c2 Qf3g3
  26	00:12	   8.032.482	623.107	+9,09	Qh5f3+ Kf1e1 Qf3g2 Ke1d1 Qg2e4 Kd1c1 Qe4f3 Kc1c2 Qf3g3
  27+	00:14	   9.459.346	634.557	+9,17	Qh5f3+ Kf1e1
  27+	00:15	   9.511.884	632.775	+9,25	Qh5f3+ Kf1e1
  27+	00:15	   9.560.452	632.054	+9,41	Qh5f3+ Kf1e1
  27+	00:15	   9.764.466	625.526	+9,73	Qh5f3+ Kf1g1
  27+	00:24	  13.585.012	559.100	+19,43	Qh5f3+ Kf1g1
  27+	00:31	  16.669.955	530.755	+29,77	Qh5f3+ Kf1e1
  27+	00:36	  19.292.002	522.266	+91,83	Qh5f3+ Kf1e1
  27	01:43	  53.109.910	512.807	+95,45	Qh5f3+ Kf1e1 Qf3xc3 d2xc3 Rg7d7 Ke1f2 Rd7d3 Kf2e2 Rd3xc3 Ke2d1 Rc3d3+ Kd1c2 Rd3d8 Kc2b2 Rd8c8 Kb2c3 Kh8g7 Kc3d4 c4c3 Bh7g8 Kg7xg8 Kd4e5 Kg8g7 Ke5d6 Rc8g8 Kd6c6 c3c2 Kc6b7 c2c1Q Kb7a6 Qc1c5

Only 14 second

[zullil]

Very impressive. Critter (with 8 threads) takes much longer:

Code: Select all

Critter Chess v1.2.1 64-bit SSE4
By Richard Vida, Slovakia

GTB Init OK

Hash table:  67108864 entries of 16 bytes = 1024 MB total
Eval cache:     32768 entries of  8 bytes =  256 KB total
Pawn hash :     65536 entries of 32 bytes =    2 MB total

8 cpu(s) detected

Opening book: "book.cbk" - 53436 entries [native]

setboard 7k/6rB/6P1/7q/2p5/2B5/3P4/5K2 b - - 0 1
go infinite
 2/ 3  00:00       287   16882  +7.14 Qf3+ Ke1 Qe4+ Kf2
 3/ 5  00:00       451   26529  +7.14 Qf3+ Ke1 Qe4+ Kf2
 4/ 7  00:00      1033   57388  +7.05 Qf3+ Ke1 Qf5 Ke2 Qd3+ Kf2
 5/10  00:00      2330  129444  +7.16 Qf3+ Ke1 Qg2 Bxg7+ Kxg7 Kd1 Qf3+ Kc2 Qd3+ Kd1
 6/10  00:00      3293  173315  +7.06 Qf3+ Ke1 Qg2 Kd1 Qg4+ Ke1 Qe6+ Kf2
 7/10  00:00      5522  276100  +7.04 Qf3+ Ke1 Qf5 Ke2 Qd3+ Kd1 Qb1+ Ke2 Qe4+ Kf2 Qf5+ Ke3
 8/12  00:00      7803  371571  +7.04 Qf3+ Ke1 Qf5 Ke2 Qe4+ Kf2 Qf4+ Ke2 Qf5 Ke3
 9/14  00:00     10944  475826  +7.06 Qf3+ Ke1 Qf5 Ke2 Qe4+ Kf2 Qd3 Kg2 Qf5 Kg3 Qg5+ Kf2 Qf4+ Ke2 Qf5 Ke3 Qd3+ Kf4 Qd6+ Kg5 Qd5+ Kf4
10/16  00:00     22368  828444  +7.00 Qf3+ Ke1 Qf5 Ke2 Qf4 Kd1 Qe4 Kc1 Qf5 Kb2 Qb5+ Kc2 Qb3+ Kc1
11/18  00:00     34881 1057000  +7.04 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa2 Kd1 Qb1+ Ke2 Qe4+ Kf2 Qf5+ Ke3 Qd3+ Kf4 Qd6+ Kg5 Qd5+ Kf4
12/19  00:00     47968 1332444  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf5+ Kb2 Qb5+ Kc2 Qb3+
13/20  00:00     69529 1616953  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf5+ Kc1 Qb5 Kc2 Qb3+
14/28  00:00    103311 1812473  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf5+ Kb2 Qb5+ Kc2 Qb3+
15/28  00:00    145622 2051014  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kd1 Qf5 Ke2 Qf4 Kd1 Qe4
16/28  00:00    205473 2308685  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kc2 Qe4+ Kb2 Qb7+ Kc2
17/28  00:00    302887 2545268  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kc2 Qe4+ Kb2 Qb7+ Kc2
18/28  00:00    502383 3044745  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kb2 Qb5+ Kc2 Qf5+ Kc1
19/28  00:00    752879 3316647  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kc2 Qh5 Kb2 Qb5+ Kc2 Qf5+ Kc1
20/30  00:00   1205093 3696604  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kc2 Qf3 Kb2 Qf1 Kc2 Qf5+ Kc1
21/30  00:00   1886861 4146947  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kc2 Qf3 Kb1 Qg3 Kc2 Qh3 Kb2 Qd3 Kc1 Qf3 Kc2
22/34  00:00   3482946 5092026  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kc2 Qf3 Kb1 Qg4 Kb2 Qf4 Kc1 Qf5 Kb2 Qb5+ Kc2 Qa4+ Kc1 Qb3 Ba1 Qb6 Kc2
23/36  00:01   5960324 5671098  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kc2 Qf3 Kb1 Qf1+ Kc2 Qg1 Bb2 Qh2 Bc3
24/36  00:01   9489993 6048434  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qd3+ Kb2 Qf5 Kc1 Qd5 Kc2 Qb5 Kc1 Qb3 Bb2 Qd3 Bc3 Qe2 Kc2 Qf3 Kb1 Qf1+ Kc2 Qg1 Bb2 Qh2 Bc3 Qf4 Kb2 Qf2 Kc2
25/38  00:02  14239549 6320261  +7.00 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qd3+ Kc1 Qf3 Bc3 Qf5 Kd1 Qd3 Kc1 Qe2 Kc2 Qg4 Kc1 Qe4 Kb2 Qf5 Kc1 Qd5 Kc2 Qb5 Kc1 Qb3 Bb2 Qd3 Bc3
26/43+ 00:03  26960112 7206659  +7.43 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qd3+ Kc1 Qf5 Bc3 Qd5 Kc2 Qf3 Kc1 Qf5 Kd1 Qd3 Kc1 Qe2 Kc2 Qf3
26/44+ 00:04  29778857 7156658  +7.87 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qe2 Bc3 Qf3 Kc1 Qf5 Kd1 Qf1+ Kc2 Qf5+ Kc1 Qd5 Kc2 Qf3
26/45+ 00:04  34375628 7024035  +8.53 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qe2 Bc3 Qf3 Kc1 Qg4 Kc2 Qf3
26/48+ 00:05  43015565 7311841  +9.51 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qh1 Bc3 Qd5 Kc1 Qd3 Kb2 Qf5 Kc1 Qd5 Kc2 Qh1 Bf6 Qe4+ Kc1 Qg4 Bc3 Qf5 Kd1 Qd3 Kc1 Qe2 Kc2 Qf3 Kc1 Qh1+ Kc2
26/50+ 00:07  56189051 7696076 +10.99 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qh3 Bc3 Qd3+ Kb2 Qf5 Kc1 Qd5 Kb2 Qd3 Kc1 Qe2 Kc2 Qf3 Kc1 Qf5 Kd1 Qd3 Kc1
26/54+ 00:11 102437270 9088569 +13.20 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qe2 Bc3 Qf3 Kc1 Qf5 Kd1 Qd3 Kc1 Qe2 Kc2
26/54+ 00:17 184680772 10455206 +16.52 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qe2 Bc3 Qf3 Kc1 Qh1+ Kc2 Qd5 Kc1 Qd3 Kb2 Qf5 Kc1 Qd5 Kc2 Qh1 Bf6 Qe4+ Kc1 Qg4 Bc3 Qf5 Kd1 Qd3 Kc1 Qe2 Kc2
26/58+ 00:25 313600033 12166357 +21.50 Qf3+ Ke1 Qg2 Kd1 Qe4 Kc1 Qb7 Kc2 Qb3+ Kc1 Qa3+ Kb1 Qf8 Kb2 Qf3 Kc2 Qf1 Bb2 Qg1 Bc3 Qh1 Bf6 Qe4+ Kc1 Qg4 Bc3 Qf5 Kd1 Qd3 Kc1 Qf1+ Kc2 Qe1 Bb2 Qh1 Bc3 Qd5 Kc1 Qd3 Kb2 Qf5 Kc1 Qd5 Kc2 Qf3 Kc1 Qf5
26/58  00:39 477678423 12158998   +M20 Qf3+ Ke1 Qxc3 dxc3 Rd7 Kf2 Rd3 Ke2 Rxc3 Kd1 Rb3 Kc1 Rb8 Kc2 Rc8 Kc3 Kg7 Kb2 c3+ Kc2 Rc6 Kd3 c2 Kd4 c1=Q Bg8 Kxg8 Ke4 Rc5 Kf3 Rc3+ Kg4 Qe3 Kh5 Qe5+ Kh4 Qg3+ Kh5 Rc5+ Kh6 Qe3#

[lech]

Very impressive. Critter (with 8 threads) takes much longer:

Thanks Louis. What about this (it is possible to win it by Qxd4(a6,b5) directly:
[d] rk6/p1p5/Bp2p3/1P6/q2B1P2/4K3/8/8 b - - 0 1

Code: Select all

Sting (beta):
   1	00:00	          84	336	+12,16	Qa4c4
   2	00:00	         227	908	+11,55	Qa4c4 Bd4e5 Qc4c5+ Ke3d3
   2	00:00	         467	1.868	+12,28	Qa4b3+ Ke3e2 Qb3d5
   3	00:00	       1.060	4.240	+12,20	Qa4b3+ Ke3e2 Qb3c4+ Ke2e3 Qc4d5
   4	00:00	       1.951	7.334	+12,12	Qa4b3+ Ke3d2 Qb3d5 Kd2e3 Qd5d6
   5	00:00	       3.647	13.710	+11,79	Qa4b3+ Ke3d2 Qb3c4 Bd4e5 Qc4e4 Kd2c3
   6	00:00	       5.385	19.163	+11,87	Qa4b3+ Ke3d2 Qb3c4 Bd4e5 Qc4e4 Kd2c3 Qe4e2 Kc3b3 Qe2d3+ Kb3a4
   7+	00:00	       7.858	26.457	+12,12	Qa4b3+ Ke3d2
   7	00:00	       8.138	27.400	+11,87	Qa4b3+ Ke3d2 Qb3c4 Bd4e5 Qc4e4 Kd2c3 Qe4e2 Kc3b3 Qe2d3+ Kb3a4 Qd3c4+
   8+	00:00	       8.953	28.603	+11,96	Qa4b3+ Ke3d2
   8	00:00	       9.940	31.757	+12,00	Qa4b3+ Ke3d2 Qb3c4 Bd4e5 Qc4e4 Kd2c3 Qe4e2 Kc3b3 Qe2d3+ Kb3a4 Qd3c4+ Ka4a3 Qc4c2
   9+	00:00	      11.621	35.429	+12,12	Qa4b3+ Ke3d2
   9	00:00	      13.366	40.750	+12,00	Qa4b3+ Ke3d2 Qb3c4 Bd4e5 Qc4e4 Kd2c3 Qe4e2 Kc3b3 Qe2d3+ Kb3a4 Qd3c4+ Ka4a3 Qc4c2
  10+	00:00	      16.363	47.566	+12,08	Qa4b3+ Ke3d2
  10+	00:00	      16.850	48.982	+12,16	Qa4b3+ Ke3d2
  10	00:00	      26.012	72.255	+12,12	Qa4b3+ Ke3d2 Qb3c4 Kd2e3 Qc4c1+ Ke3f3 Qc1f1+ Kf3e3 Qf1g1+ Ke3e4 Qg1g2+ Ke4e3 Qg2g3+ Ke3e4 Qg3h3 Bd4e5 Qh3b3
  11+	00:00	      28.558	76.154	+12,24	Qa4b3+ Ke3d2
  11	00:00	      33.895	86.687	+12,12	Qa4b3+ Ke3d2 Qb3c4 Kd2e3 Qc4c1+ Ke3f3 Qc1f1+ Kf3e3 Qf1g1+
  12-	00:00	      42.336	100.322	+12,04	Qa4b3+ Ke3d2
  12+	00:00	      47.332	108.063	+12,20	Qa4b3+ Ke3d2
  12-	00:00	      59.638	127.159	+11,95	Qa4b3+ Ke3d2
  12	00:00	      62.729	133.750	+12,28	Qa4b3+ Ke3d2 Qb3c4 Bd4e5 Qc4e4 Kd2c3 Qe4e2 Kc3b3 Qe2d3+ Kb3a4 Qd3d5 Ka4b4 Qd5f3
  13-	00:00	      76.653	153.306	+12,12	Qa4b3+ Ke3d2
  13-	00:00	      91.898	168.003	+11,95	Qa4b3+ Ke3d2
  13	00:00	     101.077	179.532	+12,20	Qa4b3+ Ke3d2 Qb3c4 Bd4e5 Qc4e4 Kd2c3 Qe4e2 Kc3b3 Qe2d3+ Kb3a4 Qd3d5 Ka4b4 Qd5f3 Kb4c4
  14	00:00	     120.852	198.118	+12,28	Qa4b3+ Ke3d2 Qb3c4 Bd4e5 Qc4e4 Kd2c3 Qe4e2 Kc3b3 Qe2d3+ Kb3a4 Qd3d5 Ka4b4 Qd5f3 Kb4c4
  15-	00:01	     348.050	322.866	+12,16	Qa4b3+ Ke3f2
  15	00:01	     395.077	332.556	+12,20	Qa4b3+ Ke3f2 Qb3c2+ Kf2e3 Qc2c1+ Ke3f3 Qc1d1+ Kf3e3 Qd1g1+
  16-	00:01	     504.816	351.054	+12,08	Qa4b3+ Ke3f2
  16	00:01	     602.291	367.026	+12,28	Qa4b3+ Ke3f2 Qb3c2+ Kf2e3 Qc2c1+ Ke3f3 Qc1d1+ Kf3e3 Qd1g1+ Ke3d3 Qg1g3+ Kd3e4 Qg3b3 Bd4f6 Qb3a3 Bf6e5
  17	00:01	     733.718	381.747	+12,28	Qa4b3+ Ke3f2 Qb3c2+ Kf2e3 Qc2c1+ Ke3f3 Qc1d1+ Kf3e3 Qd1g1+
  18	00:02	   1.033.807	401.011	+12,28	Qa4b3+ Ke3f2 Qb3c2+ Kf2e3 Qc2c1+ Ke3f3 Qc1d1+ Kf3e3 Qd1g1+
  19	00:03	   1.414.314	417.078	+12,28	Qa4b3+ Ke3f2 Qb3c2+ Kf2e3 Qc2c1+ Ke3f3 Qc1d1+ Kf3e3 Qd1g1+ Ke3d3 Qg1g3+ Kd3e4 Qg3b3 Bd4f6 Qb3a3 Bf6e5 Qa3h3
  20	00:05	   2.258.511	437.950	+12,28	Qa4b3+ Ke3f2 Qb3c2+ Kf2e3 Qc2c1+ Ke3f3 Qc1d1+ Kf3e3 Qd1e1+ Ke3d3 Qe1g3+ Kd3e4 Qg3b3 Bd4f6 Qb3a3 Bf6e5 Qa3h3
  21	00:08	   3.822.195	453.834	+12,28	Qa4b3+ Ke3f2 Qb3c2+ Kf2e3 Qc2c1+ Ke3f3 Qc1d1+ Kf3e3 Qd1e1+ Ke3d3 Qe1g3+ Kd3e4 Qg3b3 Bd4f6 Qb3a3 Bf6e5 Qa3h3 Ke4d4 Qh3f3 Kd4c4 Qf3e3 Kc4b4 Qe3d3 Kb4a4 Qd3d5 Ka4b4 Qd5f3
  22-	00:24	  11.869.489	484.765	+12,20	Qa4b3+ Ke3d2
  22-	00:38	  18.633.777	483.592	+12,12	Qa4b3+ Ke3d2
  22-	00:50	  24.798.524	487.430	+11,95	Qa4b3+ Ke3d2
  22	00:57	  28.095.876	489.679	+12,00	Qa4b3+ Ke3d2 Qb3d5 Kd2e3 Qd5g2 Bd4e5
  23+	01:01	  29.802.087	484.452	+12,28	Qa4b3+ Ke3d2
  23	01:11	  33.686.787	471.856	+12,28	Qa4b3+ Ke3d2 Qb3d5 Kd2e3 Qd5g2 Bd4e5 Qg2g3+ Ke3d2
  24	01:44	  46.951.748	450.501	+12,16	Qa4b3+ Ke3d2 Qb3d5 Kd2e3 Qd5g2 Bd4e5 Qg2g3+ Ke3d2 Qg3a3 Kd2e2 Qa3h3 Ke2f2
  25+	02:28	  63.160.203	426.254	+12,44	Qa4b3+ Ke3e2
  25+	02:28	  63.427.239	425.766	+12,72	Qa4b3+ Ke3e2
  25+	03:16	  77.924.820	396.209	+16,68	Qa4b3+ Ke3e2
  25	30:13	 555.722.615	306.359	+20,36	Qa4b3+ Ke3e2 Qb3c4+ Ke2e3 Qc4c1+ Ke3f3 Qc1f1+ Kf3e3 Qf1e1+ Ke3d3 c7c5 Bd4e5+ Qe1xe5 f4xe5 Kb8c7 Kd3c3 Ra8d8 Kc3c2 Rd8d5 Kc2c3

[zullil]

Very impressive. Critter (with 8 threads) takes much longer:

Thanks Louis. What about this (it is possible to win it by Qxd4(a6,b5) directly:
[d] rk6/p1p5/Bp2p3/1P6/q2B1P2/4K3/8/8 b - - 0 1

Critter-1.2.1 (8 threads, no tablebases) takes more than 70 minutes to see Qc4 followed by Qc1:

Code: Select all

info multipv 1 depth 30 seldepth 72 nodes 65476344366 time 4405746 nps 14861579 hashfull 0 tbhits 0 score cp 1864 lowerbound pv a4b3 e3e2 b3c4 e2e3 c4c1 e3f3 c1d2 d4e5 d2d3 f3g4 d3e4 g4g5 e4f5 g5h4 f5g6 h4h3 g6g1 h3h4 g1g8 h4h3 g8g6 h3h4 g6g1 h4h3 g1c1 h3h4 c1d1 h4g3 d1f1 e5f6 f1e1 g3g4 e1h1 g4g3 h1f1 f6e5 f1e2 g3h4 e2g2 e5f6 g2f3 f6e5 f3d5 h4g3 d5h1 g3g4 h1g2 g4h4 g2g1

[lech]

Critter-1.2.1 (8 threads, no tablebases) takes more than 70 minutes to see Qc4 followed by Qc1:

Code: Select all

info multipv 1 depth 30 seldepth 72 nodes 65476344366 time 4405746 nps 14861579 hashfull 0 tbhits 0 score cp 1864 lowerbound pv a4b3 e3e2 b3c4 e2e3 c4c1 e3f3 c1d2 d4e5 d2d3 f3g4 d3e4 g4g5 e4f5 g5h4 f5g6 h4h3 g6g1 h3h4 g1g8 h4h3 g8g6 h3h4 g6g1 h4h3 g1c1 h3h4 c1d1 h4g3 d1f1 e5f6 f1e1 g3g4 e1h1 g4g3 h1f1 f6e5 f1e2 g3h4 e2g2 e5f6 g2f3 f6e5 f3d5 h4g3 d5h1 g3g4 h1g2 g4h4 g2g1

I don’t believe that Critter solved it. Rather not.
Conclusion: intelligence of engines is a matter of software not machines.
Now I have holiday. Sting will be ready later.

[zullil]

This is from later in the same search:

Code: Select all

info multipv 1 depth 30 seldepth 80 nodes 182638178704 time 11390642 nps 16034054 hashfull 0 tbhits 0 score mate 28 pv a4b3 e3e2 b3c4 e2e3 c4c1 e3f3 c1d1 f3e3 d1e1 e3d3 c7c6 d4f6 e1g3 d3e2 g3f4 f6d8 f4e4 e2d2 c6b5 d2c1 e4c4 c1b2 c4d4 b2a3 d4d8 a6b5 d8d4 b5e8 d4a1 a3b3 b8c7 e8h5 a8d8 h5g6 d8f8 g6e4 a1d4 e4c2 

Remember that an engine doesn't need to find the entire line, as long as each move it makes is best at the moment!