Distance to mate

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thewhip
Posts: 22
Joined: Thu Sep 20, 2018 8:50 pm
Full name: Juan Garcia

Distance to mate

Post by thewhip » Fri Mar 13, 2020 1:45 pm

What is the shortest distance to mate?
I found it in 23 moves, with my modest engine, but I'm not sure.
Kubbel, 1922

Joost Buijs
Posts: 1176
Joined: Thu Jul 16, 2009 8:47 am
Location: Almere, The Netherlands

Re: Distance to mate

Post by Joost Buijs » Fri Mar 13, 2020 2:26 pm

thewhip wrote:
Fri Mar 13, 2020 1:45 pm
What is the shortest distance to mate?
I found it in 23 moves, with my modest engine, but I'm not sure.
Kubbel, 1922
After a long search my engine finds a mate in 22, but I'm not sure if this is correct.

Code: Select all

info depth 29 score mate 22 time 265456 nodes 2008266933 nps 7565347 tbhits 66450254 pv h4f6 a3a2 c8b6 d5c5 b6a4 c5d5 a4c3 d5c5 f6d4 c5d4
I get the PV from the hash-table so it is a bit truncated, also a table-base hit will truncate the PV

JohnWoe
Posts: 228
Joined: Sat Mar 02, 2013 10:31 pm

Re: Distance to mate

Post by JohnWoe » Fri Mar 13, 2020 2:30 pm

Stockfish 120220 64
Mate in #19

Code: Select all

65	  #19 	1,11G	7:08.31	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 a2 Kb5 Kf7 d4 Ke7 d5 Kd6 Ba1 Ke7 Kc5 Kf7 d6 Ke6 d7 Kf5 d8=Q Kf4 Qf8+ Kg3 Nd5 Kg4 Ne3+ Kh4 Qf2+ Kh3 Qg2+ Kh4 Qg4# 
 64	  #19 	1,09G	6:56.46	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 a2 Kb5 Kf7 d4 Ke7 d5 Kd6 Ba1 Ke7 Kc5 Kf7 d6 Ke6 d7 Kf5 d8=Q Kf4 Qf8+ Kg3 Nd5 Kg4 Ne3+ Kh4 Qf2+ Kh3 Qg2+ Kh4 Qg4# 
 63	  #19 	999,8M	6:23.38	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 a2 Kb5 Kf7 d4 Ke7 d5 Kd6 Ba1 Ke7 Kc5 Kf7 d6 Ke6 d7 Kf5 d8=Q Kf4 Qf8+ Kg3 Nd5 Kg4 Ne3+ Kh4 Qf2+ Kh3 Qg2+ Kh4 Qg4# 
 62	  #19 	933,4M	5:56.83	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 Ke7 d4 Ke6 d5+ Kd6 Bb4+ Ke5 Bxa3 Ke4 d6 Kd3 Nd5 Kxd2 Bc5 Ke2 Ne3 Kf3 d7 Kg3 d8=Q Kf2 Qf8+ Ke2 Qf1+ Kd2 Qd1+ Kc3 Qc2# 
 61	  #19 	836,8M	5:17.95	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 Ke7 d4 Ke6 d5+ Kd6 Bb4+ Ke5 Bxa3 Ke4 d6 Kd3 Nd5 Kxd2 Bc5 Ke2 Ne3 Kf3 d7 Kg3 d8=Q Kf2 Qf8+ Ke2 Qf1+ Kd2 Qd1+ Kc3 Qc2# 
 60	  #19 	796,1M	5:01.05	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 Ke7 d4 Ke6 d5+ Kd6 Bb4+ Ke5 Bxa3 Ke4 d6 Kd3 Nd5 Kxd2 Bc5 Ke2 Ne3 Kf3 d7 Kg3 d8=Q Kf2 Qf8+ Ke2 Qf1+ Kd2 Qd1+ Kc3 Qc2# 
 59	  #19 	737,2M	4:38.44	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 Ke7 d4 a2 d5 Kd6 Kb5 Ke7 Kc5 Kf7 d6 Ke6 d7 a1=Q Bxa1 Kf5 d8=Q Kf4 Nc4 Kg4 Qf6 Kh5 Be5 Kg4 Ne3+ Kh5 Qf5+ Kh4 Ng2# 
 58	  #19 	687,8M	4:18.92	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 Ke7 d4 a2 d5 Kd6 Kb5 Ke7 Kc5 Kf7 d6 Ke6 d7 a1=Q Bxa1 Kf5 d8=Q Kf4 Nc4 Kg4 Qf6 Kh5 Be5 Kg4 Ne3+ Kh5 Qf5+ Kh4 Ng2# 
 57	  #19 	661,5M	4:08.87	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Bc3 Ke7 d4 a2 d5 Kd6 Kb5 Ke7 Kc5 Kf7 d6 Ke6 d7 a1=Q Bxa1 Kf5 d8=Q Kf4 Nc4 Kg4 Qf6 Kh5 Be5 Kg4 Ne3+ Kh5 Qf5+ Kh6 Ng4# 
 56	  #20 	471,9M	2:58.16	Nb6+ Ke6 Bf2 d3 cxd3 Kf7 Bd4 Ke6 Ba1 Ke7 d4 Kd6 d5 Ke7 Bc3 Kd6 Bb4+ Ke5 Bxa3 Ke4 d6 Kd3 Nd5 Kxd2 Bc5 Ke2 Ne3 Kf3 d7 Kg3 d8=Q Kf2 Qf8+ Ke1 Qf1+ Kd2 Qd1+ Kc3 Qc2# 
 55	  #21 	352,4M	2:14.91	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kf5 Bd4 Kg4 Ba1 Kf5 d4 Ke6 Nb6 Kd6 d5 Ke7 Kb5 Kf7 d6 Ke6 d7 Ke7 Bd4 Ke6 d8=Q Kf5 Qh4 Kg6 Qf6+ Kh5 Qf5+ Kh6 Qg4 Kh7 Qg7# 
 54	  #21 	321,8M	2:03.18	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kf5 Bd4 Kg4 Ba1 Kf5 d4 Ke6 Nb6 Kd6 d5 Ke7 Kb5 Kf7 d6 Ke6 d7 Ke7 Bd4 Ke6 d8=Q Kf5 Qh4 Kg6 Qf6+ Kh5 Qf5+ Kh6 Qg4 Kh7 Qg7# 
 53	  #21 	267,7M	1:42.44	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kf5 Bd4 Kg4 Ba1 Kf3 Kb5 Kg3 d4 Kg4 d5 Kf5 Nb6 Kg5 d6 Kg4 d7 Kg3 d8=Q Kf4 Nc4 Kg4 Ne3+ Kf3 Bc3 Ke4 Qf8 Kd3 Qf5+ Ke2 Qf1# 
 52	  #22 	222,0M	1:25.85	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kd5 Be3 Kc6 Bd4 Kc7 Ba1 Kd7 d4 Ke6 Nb6 Kd6 d5 Ke7 Kb5 Kf7 d6 Ke6 d7 Ke7 d3 Ke6 d8=Q Kf5 Qh4 Kg6 Qg4+ Kf7 Qg7+ Ke8 Bd4 Kd8 Qd7# 
 51	  #22 	199,8M	1:16.80	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kd5 Be3 Kc6 Bd4 Kc7 Ba1 Kd7 d4 Ke6 Nb6 Kd6 d5 Ke7 Kb5 Kf7 d6 Ke6 d7 Ke7 d3 Ke6 d8=Q Kf5 Qh4 Kg6 Qg4+ Kf7 Qg7+ Ke8 Bd4 Kd8 Qd7# 
 50	  #22 	183,8M	1:10.29	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kd5 Be3 Kc6 Bd4 Kc7 Ba1 Kd7 d4 Ke6 Nb6 Kd6 d5 Kc5 Bc3 Kd6 Bf6 Kc5 Ka5 Kd6 Kb5 Kc7 Be7 Kb7 d6 Ka7 d7 Kb8 d8=Q+ Kb7 Qa8+ Kc7 Qa7# 
 49	  #22 	169,6M	1:04.36	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kd5 Be3 Kc6 Bd4 Kc7 Ba1 Kd7 d4 Ke6 Nb6 Kd6 d5 Kc5 Bc3 Kd6 Bf6 Kc5 Ka5 Kd6 Kb5 Kc7 Be7 Kb7 d6 Ka7 d7 Kb8 d8=Q+ Kb7 Qa8+ Kc7 Qa7# 
 48	  #22 	161,8M	1:00.66	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kd5 Be3 Kc6 Bd4 Kc7 Ba1 Kd7 d4 Ke6 Nb6 Kd6 d5 Kc5 Bc3 Kd6 Bf6 Kc5 Ka5 Kd6 Kb5 Kc7 Be7 Kb7 d6 Ka7 d7 Kb8 d8=Q+ Kb7 Qa8+ Kc7 Qa7# 
 47	  #22 	151,2M	0:56.09	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kd5 Be3 Kc6 Bd4 Kc7 Ba1 Kd7 d4 Ke6 Nb6 Kd6 d5 Kc5 Bc3 Kd6 Bf6 Kc5 Ka5 Kd6 Kb5 Kc7 Be7 Kb7 d6 Ka7 d7 Kb8 d8=Q+ Kb7 Qa8+ Kc7 Qa7# 
 46	  #22 	143,9M	0:53.20	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kd5 Be3 Kc6 Bd4 Kc7 Ba1 Kd7 d4 Ke6 Nb6 Kd6 d5 Kc5 Bc3 Kd6 Bf6 Kc5 Ka5 Kd6 Kb5 Kc7 Be7 Kb7 d6 Ka7 d7 Kb8 d8=Q+ Kb7 Qa8+ Kc7 Qa7# 
 45	  #22 	137,5M	0:50.14	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Nc4 Kd5 Be3 Kc6 Bd4 Kc7 Ba1 Kd7 d4 Ke6 Nb6 Kd6 d5 Kc5 Bc3 Kd6 Bf6 Kc5 Ka5 Kd6 Kb5 Kc7 Be7 Kb7 d6 Ka7 d7 Kb8 d8=Q+ Kb7 Qa8+ Kc7 Qa7# 
 44	  #23 	124,9M	0:45.53	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Be3 Ke5 Nc4+ Kd5 Bf2 Ke6 Bd4 Kd5 Ba1 Kc5 Nb6 Kb4 d4 Ka3 d5 Ka2 Bg7 Kb3 d6 Kc2 d7 Kd1 d8=Q Ke1 Qd3 Kf2 Nc4 Kg2 Ne3+ Kf3 Qf1+ Kg3 Qg2+ Kf4 Qg4# 
 43	  #23 	118,4M	0:43.03	Nb6+ Ke6 Bf2 d3 cxd3 Ke5 Nc4+ Kf6 Nxa3 Ke6 Be3 Ke5 Nc4+ Kd5 Bf2 Ke6 Bd4 Kd5 Ba1 Kc5 Nb6 Kb4 d4 Ka3 d5 Ka2 Bg7 Kb3 d6 Kc2 d7 Kd1 d8=Q Ke1 Qd3 Kf2 Nc4 Kg2 Ne3+ Kf3 Qf1+ Kg3 Qg2+ Kf4 Qg4# 
 42	  #24 	99,9M  	0:35.74	Nb6+ Ke6 Bf2 Ke5 Nc4+ Kf5 Nxa3 d3 cxd3 Ke6 Kb5 Ke5 Bc5 Ke6 Bd4 Kf5 Ba1 Kf4 d4 Ke4 Nc4 Kd5 Nb6+ Kd6 d5 Ke7 Bc3 Ke8 d6 Kf7 d7 Ke7 Ba1 Kf7 d8=Q Kg6 Nc4 Kf5 Ne3+ Ke4 Qd5+ Kf4 Qf5+ Kg3 Be5+ Kh4 Ng2# 
 41	  #24 	90,1M  	0:32.39	Nb6+ Ke6 Bf2 Ke5 Nc4+ Kf5 Nxa3 d3 cxd3 Ke6 Kb5 Ke5 Bc5 Ke6 Bd4 Kf5 Ba1 Kf4 d4 Ke4 Nc4 Kd5 Nb6+ Ke6 d5+ Ke7 Kc5 Kf7 d6 Ke8 d7+ Ke7 Kb5 Ke6 d8=Q Kf5 Nc4 Kg4 Ne3+ Kf3 Bc3 Ke4 Qf8 Kd3 Qf5+ Ke2 Qf1# 
 40	  #34 	68,2M  	0:24.39	Nb6+ Ke6 Bf2 Ke5 Nc4+ Kd5 Nxa3 d3 cxd3 Ke6 Kb5 Ke5 Bc5 Ke6 Bd4 Kf5 Ba1 Kf4 d4 Ke4 Nc4 Kd3 d5 Kc2 d6 Kb1 Bh8 Kc1 d7 Kd1 d8=Q Ke2 Ba1 Ke1 Nb6 Kd1 Qc8 Ke2 Qc4+ Ke1 Qa2 Ke2 
 40	  #66!	58,3M  	0:20.71	Nb6+! 
My engine after 1.2 billion nodes I doubt it finds it.

Code: Select all

exclude: none best +tail                                          
dep	score	nodes	time	(not shown:  tbhits	knps	seldep)
 16	+6,81 	1,18G	3:06.92	Nb6+ 
 15	+6,77 	289,7M	0:47.01	Nb6+ 
 14	+6,78 	100,7M	0:17.66	Nb6+ 
 13	+6,71 	42,5M  	0:07.09	Nb6+ 
 12	+6,59 	12,1M  	0:02.40	Nb6+ 
 11	+6,65 	4,37M  	0:00.94	Nb6+ 
 10	+6,56 	1,79M  	0:00.51	Nb6+ 
  9	+6,57 	690057	0:00.31	Nb6+ 
  8	+6,48 	261080	0:00.18	Nb6+ 
  7	+6,45 	125805	0:00.11	Nb6+ 
  6	+6,36 	52152  	0:00.07	Nb6+ 
  5	+5,71 	17917  	0:00.03	Nb6+ 
  4	+5,55 	6921    	0:00.01	Nb6+ 
  3	+5,53 	1905    	0:00.00	Nb6+ 
  2	+5,56 	457      	0:00.00	Nb6+ 
  1	+5,54 	55        	0:00.00	Nb6+ 
  0	# 

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MikeB
Posts: 4415
Joined: Thu Mar 09, 2006 5:34 am
Location: Pen Argyl, Pennsylvania

Re: Distance to mate

Post by MikeB » Fri Mar 13, 2020 2:57 pm

Joost Buijs wrote:
Fri Mar 13, 2020 2:26 pm
thewhip wrote:
Fri Mar 13, 2020 1:45 pm
What is the shortest distance to mate?
I found it in 23 moves, with my modest engine, but I'm not sure.
Kubbel, 1922
After a long search my engine finds a mate in 22, but I'm not sure if this is correct.

Code: Select all

info depth 29 score mate 22 time 265456 nodes 2008266933 nps 7565347 tbhits 66450254 pv h4f6 a3a2 c8b6 d5c5 b6a4 c5d5 a4c3 d5c5 f6d4 c5d4
I get the PV from the hash-table so it is a bit truncated, also a table-base hit will truncate the PV
Honey confirm the mate in 19.
MichaelB7@VM-894787 MINGW64 /c/cluster.mfb/Popcnt-LP
# Honey-dev-031020
Honey 031020 by M. Byrne and scores of others...
info string Hash LargePages 256 Mb
p f 2N5/8/K7/3k4/3p3B/p7/2PP4/8 w - - 0 0
s t 32
Confirmation: Threads set to 32
s h 2048
info string Hash LargePages 2048 Mb
Confirmation: Hash set to 2048
s z c:/syzygy
info string Found 510 tablebases
Confirmation: SyzygyPath set to c:/syzygy
g i m 19
...
info depth 60 seldepth 40 multipv 1 score mate 19 nodes 2253591962 nps 89992491 hashfull 994 tbhits 166858259 time 25042 pv c8b6 d5e6 h4f2 d4d3 c2d3 e6e5 b6c4 e5d5 c4a3 d5c6 a3c4 c6d5 a6b6 d5e6 f2d4 e6d5 d4c3 d5e6 b6c6 e6e7 d3d4 e7f8 d4d5 f8g8 d5d6 g8f8 d6d7 f8f7 d7d8q f7g6 c4e3 g6f7 d8f6 f7e8 f6g7 e8d8 g7d7
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thewhip
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Full name: Juan Garcia

Re: Distance to mate

Post by thewhip » Fri Mar 13, 2020 3:20 pm

This is the analysis found it by my engine:

Analysis by CoVid 1.9 X64:
1.Nc6 Kxc6 2. Bf6 Kd5 3. d3 a2 4. c4+ dxc3 5. Bxc3 Kc5 6. d4+ Kc4 7. Bb2
Kb3 8. Ba1 Kc4 9. Kb6 Kd5 10. Kc7 Ke4 11. Kc6 Kd3 12. d5 Kc2 13. d6 Kb1
14. Bd4 a1=Q 15. Bxa1 Kxa1 16. d7 Kb1 17. d8=Q Kc2 18. Qd7 Kb2 19. Qd2+
Kb1 20. Kc5 Ka1 21. Kc4 Kb1 22. Kc3 Ka1 23. Qb2#
+- (#23) Depth: 44/62 00:01:20

thewhip
Posts: 22
Joined: Thu Sep 20, 2018 8:50 pm
Full name: Juan Garcia

Re: Distance to mate

Post by thewhip » Fri Mar 13, 2020 3:37 pm

The question, then, is whether to take the knight or not.
If I take the knight 23 moves and if I don't take it 19 moves. Interesting.

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MikeB
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Location: Pen Argyl, Pennsylvania

Re: Distance to mate

Post by MikeB » Fri Mar 13, 2020 3:47 pm

thewhip wrote:
Fri Mar 13, 2020 3:20 pm
This is the analysis found it by my engine:

Analysis by CoVid 1.9 X64:
1.Nc6 Kxc6 2. Bf6 Kd5 3. d3 a2 4. c4+ dxc3 5. Bxc3 Kc5 6. d4+ Kc4 7. Bb2
Kb3 8. Ba1 Kc4 9. Kb6 Kd5 10. Kc7 Ke4 11. Kc6 Kd3 12. d5 Kc2 13. d6 Kb1
14. Bd4 a1=Q 15. Bxa1 Kxa1 16. d7 Kb1 17. d8=Q Kc2 18. Qd7 Kb2 19. Qd2+
Kb1 20. Kc5 Ka1 21. Kc4 Kb1 22. Kc3 Ka1 23. Qb2#
+- (#23) Depth: 44/62 00:01:20
hmmm CoVid 1.9 ...very interesting ...
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Nordlandia
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Re: Distance to mate

Post by Nordlandia » Fri Mar 13, 2020 3:50 pm

I can try god ol' nalimov :D

Dann Corbit
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Re: Distance to mate

Post by Dann Corbit » Fri Mar 13, 2020 4:12 pm

Nordlandia wrote:
Fri Mar 13, 2020 3:50 pm
I can try god ol' nalimov :D
They're good, but not that good
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.

thewhip
Posts: 22
Joined: Thu Sep 20, 2018 8:50 pm
Full name: Juan Garcia

Re: Distance to mate

Post by thewhip » Fri Mar 13, 2020 4:17 pm

Sorry, I misplaced the knight on the chessboard. :oops:
This is the correct one:

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