Mate in 12, but impossible ...

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chrisw
Posts: 4585
Joined: Tue Apr 03, 2012 4:28 pm
Location: Midi-Pyrénées
Full name: Christopher Whittington

Mate in 12, but impossible ...

Post by chrisw »

This one has been on Agadmator's channel for ten days, surprising nobody posted it, I guess some might think it falls into the dreaded forbidden class: chess positions unsolvable by engines, but, then again, it's a very beautiful position AND a forced mate in 12. 70 ply deep doesn't find it though.

https://www.youtube.com/watch?v=ZNnIsmHjcjE
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F.Huber
Posts: 854
Joined: Thu Mar 09, 2006 4:50 pm
Location: Austria

Re: Mate in 12, but impossible ...

Post by F.Huber »

chrisw wrote: ↑Wed Jul 31, 2024 8:42 pm This one has been on Agadmator's channel for ten days, surprising nobody posted it, I guess some might think it falls into the dreaded forbidden class: chess positions unsolvable by engines, but, then again, it's a very beautiful position AND a forced mate in 12. 70 ply deep doesn't find it though.

https://www.youtube.com/watch?v=ZNnIsmHjcjE
Impossible? ChestUCI finds #12 in about 1 min (in 'Normal' mode) and in 3 sec (in 'AutoTurbo' mode)!

ChestUCI Ver.5.2:
FEN: n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - (4+6)
Stellungs-Analyse: C0/R0/K3/P6/X22 W:4/25
Suche nach Matt in 12 ... (Hash=256MB)
12 00:53 46.678.802 969.224 +M12 1.Bc7
Suche abgeschlossen ... (Zeit=79.80s)
Matt in 12 gefunden ! (1 Lösung in 01:19)
12/12 01:19 74.607.332 934.870 +M12 1.Bc7 Qxc8 2.gxf7+ Kh8 3.Be5 Qc5 4.Bb2 Nc7 5.Ba1 a4 6.Bb2 a3 7.Ba1 a2 8.Bb2 a1Q 9.Bxa1 Nd5+ 10.Ke6+ Nc3 11.Bxc3+ Qe5+ 12.Bxe5+
Best move: Bc7, Value: +Mate in 12, Depth: 12/12, Time: 01:19,854, 74.607.332 Nodes, 934.870 N/sec

ChestUCI Ver.5.2:
FEN: n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - (4+6)
Stellungs-Analyse: C0/R0/K3/P6/X22 W:4/25
AutoTurbo-Suche nach Spezial-Matt [C1/R0/K0/P0/X0] in 12 ... (Hash=256MB)
AutoTurbo-Suche nach Spezial-Matt [C0/R1/K0/P0/X0] in 12 ... (Hash=256MB)
AutoTurbo-Suche nach Spezial-Matt [C0/R2/K0/P0/X0] in 12 ... (Hash=256MB)
AutoTurbo-Suche nach Spezial-Matt [C0/R-2/K0/P0/X0] in 12 ... (Hash=256MB)
AutoTurbo-Suche nach Spezial-Matt [C0/R3/K0/P0/X0] in 12 ... (Hash=256MB)
AutoTurbo-Suche nach Spezial-Matt [C0/R-3/K0/P0/X0] in 12 ... (Hash=256MB)
AutoTurbo-Suche nach Spezial-Matt [C0/R0/K1/P0/X0] in 12 ... (Hash=256MB)
AutoTurbo-Suche nach Spezial-Matt [C0/R0/K2/P0/X0] in 12 ... (Hash=256MB)
AutoTurbo-Suche nach Spezial-Matt [C0/R0/K3/P0/X0] in 12 ... (Hash=256MB)
12/12 00:02 575.109 857.092 +M12 1.Bc7
12/12 00:02 1.078.847 933.258 +M12 1.Bc7 Qxc8 2.gxf7+ Kh8 3.Be5 Qc5 4.Bb2 Nc7 5.Ba1 a4 6.Bb2 a3 7.Ba1 a2 8.Bb2 a1Q 9.Bxa1 Nd5+ 10.Ke6+ Nc3 11.Bxc3+ Qe5+ 12.Bxe5+
AutoTurbo-Suche nach Spezial-Matt [C0/R0/K3/P0/X35] in 12 ... (Hash=256MB)
12/12 00:04 428.867 785.470 +M12 1.Bc7
12/12 00:04 932.250 904.219 +M12 1.Bc7 Qxc8 2.gxf7+ Kh8 3.Be5 Qc5 4.Bb2 Nc7 5.Ba1 a4 6.Bb2 a3 7.Ba1 a2 8.Bb2 a1Q 9.Bxa1 Nd5+ 10.Ke6+ Nc3 11.Bxc3+ Qe5+ 12.Bxe5+
Matt in 12 gefunden ! (1 Lösung in 00:01)
12/12 00:04 932.250 904.219 +M12 1.Bc7 Qxc8 2.gxf7+ Kh8 3.Be5 Qc5 4.Bb2 Nc7 5.Ba1 a4 6.Bb2 a3 7.Ba1 a2 8.Bb2 a1Q 9.Bxa1 Nd5+ 10.Ke6+ Nc3 11.Bxc3+ Qe5+ 12.Bxe5+
Best move: Bc7, Value: +Mate in 12, Depth: 12/12, Time: 00:04,058, 932.250 Nodes, 904.219 N/sec
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MMarco
Posts: 211
Joined: Sun Apr 12, 2020 1:09 am
Full name: Marc-O Moisan-Plante

Re: Mate in 12, but impossible ...

Post by MMarco »

chrisw wrote: ↑Wed Jul 31, 2024 8:42 pm This one has been on Agadmator's channel for ten days, surprising nobody posted it, I guess some might think it falls into the dreaded forbidden class: chess positions unsolvable by engines, but, then again, it's a very beautiful position AND a forced mate in 12. 70 ply deep doesn't find it though.

https://www.youtube.com/watch?v=ZNnIsmHjcjE
Nice mate. Crystal 8.0 on one thread:

[d]n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - 0 1

Code: Select all

Analysis by Crystal 8:

1.gxf7+ Dxf7+ 2.Re5 De8+ 3.Rf6 
  La position est équilibrée: = (0.00)  Profondeur: 10/22   00:00:00
1.gxf7+ Dxf7+ 2.Re5 De8+ 3.Rf6 
  La position est équilibrée: = (0.00)  Profondeur: 11/22   00:00:00
1.gxf7+ Dxf7+ 2.Re5 De8+ 3.Rf6 
  La position est équilibrée: = (0.00)  Profondeur: 12/22   00:00:00
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 
  Les Blancs sont nettement mieux: +- (1.76)  Profondeur: 13/22   00:00:00  241kN, tb=912
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 
  Les Blancs ont un avantage décisif: +- (3.11)  Profondeur: 14/22   00:00:00  281kN, tb=1005
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 Dd4+ 9.Fxd4 
  Les Blancs sont clairement gagnants: +- (4.69)  Profondeur: 15/28   00:00:00  334kN, tb=1209
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 
  Les Blancs sont clairement gagnants: +- (7.03)  Profondeur: 16/28   00:00:00  431kN, tb=1750
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 17/28   00:00:00  692kN, tb=3357
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 18/28   00:00:00  830kN, tb=4562
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 19/28   00:00:00  961kN, tb=5847
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 20/28   00:00:00  1100kN, tb=7286
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 21/28   00:00:00  1266kN, tb=9148
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 22/28   00:00:00  1442kN, tb=10910
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 23/23   00:00:01  1650kN, tb=13015
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 24/23   00:00:01  1893kN, tb=15378
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 25/23   00:00:01  2188kN, tb=18688
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 26/23   00:00:01  2503kN, tb=22076
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 27/23   00:00:01  2910kN, tb=26367
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 28/23   00:00:01  3388kN, tb=31515
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 29/23   00:00:01  3927kN, tb=37542
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 30/23   00:00:01  4629kN, tb=45698
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 31/23   00:00:01  5331kN, tb=54161
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 32/23   00:00:02  6199kN, tb=66516
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 33/23   00:00:02  7052kN, tb=76949
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 34/23   00:00:02  8115kN, tb=91096
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 35/23   00:00:02  9248kN, tb=104709
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 36/23   00:00:03  10559kN, tb=120506

(,  31.07.2024)
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chrisw
Posts: 4585
Joined: Tue Apr 03, 2012 4:28 pm
Location: Midi-Pyrénées
Full name: Christopher Whittington

Re: Mate in 12, but impossible ...

Post by chrisw »

MMarco wrote: ↑Wed Jul 31, 2024 9:45 pm
chrisw wrote: ↑Wed Jul 31, 2024 8:42 pm This one has been on Agadmator's channel for ten days, surprising nobody posted it, I guess some might think it falls into the dreaded forbidden class: chess positions unsolvable by engines, but, then again, it's a very beautiful position AND a forced mate in 12. 70 ply deep doesn't find it though.

https://www.youtube.com/watch?v=ZNnIsmHjcjE
Nice mate. Crystal 8.0 on one thread:

[d]n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - 0 1

Code: Select all

Analysis by Crystal 8:

1.gxf7+ Dxf7+ 2.Re5 De8+ 3.Rf6 
  La position est équilibrée: = (0.00)  Profondeur: 10/22   00:00:00
1.gxf7+ Dxf7+ 2.Re5 De8+ 3.Rf6 
  La position est équilibrée: = (0.00)  Profondeur: 11/22   00:00:00
1.gxf7+ Dxf7+ 2.Re5 De8+ 3.Rf6 
  La position est équilibrée: = (0.00)  Profondeur: 12/22   00:00:00
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 
  Les Blancs sont nettement mieux: +- (1.76)  Profondeur: 13/22   00:00:00  241kN, tb=912
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 
  Les Blancs ont un avantage décisif: +- (3.11)  Profondeur: 14/22   00:00:00  281kN, tb=1005
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 Dd4+ 9.Fxd4 
  Les Blancs sont clairement gagnants: +- (4.69)  Profondeur: 15/28   00:00:00  334kN, tb=1209
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 
  Les Blancs sont clairement gagnants: +- (7.03)  Profondeur: 16/28   00:00:00  431kN, tb=1750
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 17/28   00:00:00  692kN, tb=3357
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 18/28   00:00:00  830kN, tb=4562
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 19/28   00:00:00  961kN, tb=5847
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 20/28   00:00:00  1100kN, tb=7286
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 21/28   00:00:00  1266kN, tb=9148
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 22/28   00:00:00  1442kN, tb=10910
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 23/23   00:00:01  1650kN, tb=13015
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 24/23   00:00:01  1893kN, tb=15378
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 25/23   00:00:01  2188kN, tb=18688
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 26/23   00:00:01  2503kN, tb=22076
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 27/23   00:00:01  2910kN, tb=26367
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 28/23   00:00:01  3388kN, tb=31515
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 29/23   00:00:01  3927kN, tb=37542
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 30/23   00:00:01  4629kN, tb=45698
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 31/23   00:00:01  5331kN, tb=54161
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 32/23   00:00:02  6199kN, tb=66516
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 33/23   00:00:02  7052kN, tb=76949
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 34/23   00:00:02  8115kN, tb=91096
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 35/23   00:00:02  9248kN, tb=104709
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Dd4+ 10.Fxd4 Cd5+ 11.Re6+ Cf6 12.Fxf6# 
  Les Blancs font mat: +- (#12)  Profondeur: 36/23   00:00:03  10559kN, tb=120506

(,  31.07.2024)
Is Crystal a matefinder, because obviously matefinders will find mates. What's interesting is what prevents (allegedly) the SF-model from finding a M12 with 70 plies of nominal search. Give SF the first move and the solution is almost immediate.
Top
peter
Posts: 3276
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: Mate in 12, but impossible ...

Post by peter »

It's a position derived from a Matous- study with first move cut off:
[pgn][Event "1.hm Szachy#0645"]
[Site "?"]
[Date "1975.??.??"]
[Round "?"]
[White "Matous=M"]
[Black "(+4013.13f6f8) (v)"]
[Result "1-0"]
[SetUp "1"]
[FEN "n2Bqk2/5p1p/5KP1/p7/6Q1/8/8/8 w - - 0 1"]
[PlyCount "25"]
[EventDate "1975.??.??"]

{Szachy=12(348) Szachy/12.} 1. Qc8 $1 (1. g7+ $2 Kg8) 1... Kg8 (1... Qe6+ 2. Qxe6 fxe6 3. gxh7) (1... Nc7 2. Be7+ Kg8 3. gxf7+) 2. Bc7 $1 Qxc8 (2... Nxc7 3. gxf7+) 3. gxf7+ Kh8 (3... Kf8 4. Bd6#) 4. Be5 $1 Qc5 $1 5. Bb2 $1 (5. Ba1 $2 Nc7 6. Bb2 a4 7. Ba1 a3) 5... Nc7 $1 6. Ba1 a4 7. Bb2 a3 8. Ba1 a2 9. Bb2 a1=Q 10. Bxa1 Nb5 11. Ke6+ Nc3 12. Bxc3+ Qxc3 13. f8=Q# 1-0
[/pgn]
n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - 0 1

Analysis by ShashChess dev-20240623-119bbad4 single thread (3.5GHz) 1G hash, Syzygy ProbeLimit 0, High Tal true:

Code: Select all

2.gxh7+ Kh8 3.Dxa8 De6+ 4.Kg5 Kxh7 5.Lxa5 f6+ 6.Kh4 Dc4+ 7.Kg3 f5 8.Db7+ Kg6 
  Die Stellung ist ausgeglichen.  
  = (-0.01)  Tiefe: 10/20   00:00:00
...
2.gxh7+ Kh8 3.Dxa8 De6+ 4.Kg5 Kxh7 5.Dxa5 De3+ 6.Kg4 De4+ 7.Kg3 De3+ 8.Kg2 De2+ 9.Kg1 De3+ 10.Kf1 Df3+ 11.Ke1 
  Die Stellung ist ausgeglichen.  
  = (0.00)  Tiefe: 23/17   00:00:02  293kN
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 De5+ 11.Lxe5 Sd5+ 12.Ke6+ Sf6 13.Lxf6# 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 24/34   00:00:03  486kN
...
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 De5+ 11.Lxe5 Sd5+ 12.Ke6+ Sf6 13.Lxf6# 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 56/24   00:00:08  7001kN
Analysis by Dragon 3.3 by Komodo Chess 64-bit single thread (3.5GHz) 1G hash, Use Syzygy false:

Code: Select all

2.Dxa8 
  Die Stellung ist ausgeglichen.  
  = (-0.09)  Tiefe: 1   00:00:03  6Knoten
...
2.gxh7+ Kh8 3.Dxa8 De6+ 4.Kg5 Dg6+ 5.Kf4 Dd6+ 6.Ke3 Dc5+ 7.Ke2 Dc2+ 8.Ke3 
  Die Stellung ist ausgeglichen.  
  = (0.05)  Tiefe: 7   00:00:03  4416Knoten
2.Lc7 a4 
  Die Stellung ist ausgeglichen.  
  = (0.10 ++)  Tiefe: 7   00:00:03  4730Knoten
...
2.Lc7 Dxc8 3.gxf7+ 
  Weiß steht deutlich besser.  
  +- (1.73 ++)  Tiefe: 7   00:00:03  4975Knoten
...
2.Lc7 Sxc7 3.gxf7+ Kf8 4.fxe8D+ Sxe8+ 5.Ke6 h5 6.Dc5+ Kg8 7.Dc4 Sg7+ 8.Ke7+ Kh7 9.Dc2+ Kh8 10.Db2 Kg8 
  Weiß steht klar auf Gewinn.  
  +- (8.52 ++)  Tiefe: 17   00:00:04  283kN
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 17   00:00:04  293kN
...
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 Sd5+ 11.Ke6+ Sc3 12.Lxc3+ Dxc3 13.f8D# 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 40   00:00:10  3984kN
n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - 0 1
Analysis by CorChess 4 dev-20240712-5bab62d7 single thread, (3.5GHz), 1G hash, Syzygy ProbeLimit 0:

Code: Select all

 
2.gxf7+ Dxf7+ 3.Ke5 De8+ 4.Kd4 Sb6 5.Dg4+ Kf8 6.Df5+ Df7 7.Dxf7+ Kxf7 8.Lxb6 
  Die Stellung ist ausgeglichen.  
  = (0.07)  Tiefe: 10/15   00:00:00
...
2.gxh7+ Kh8 3.Dxa8 De6+ 4.Kg5 De5+ 5.Kh6 Dg7+ 6.Kh5 Dg6+ 7.Kh4 Dh6+ 8.Kg4 De6+ 9.Kf3 Df5+ 10.Ke3 De5+ 11.Kd3 Dd6+ 12.Kc4 Db4+ 13.Kd5 Dd2+ 14.Kc5 Db4+ 
  Die Stellung ist ausgeglichen.  
  = (0.00)  Tiefe: 35/27   00:00:18  2653kN
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 Dd4+ 11.Lxd4 Sd5+ 12.Ke6+ Sf6 13.Lxf6# 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 36/28   00:00:21  3306kN
...
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 Dd4+ 11.Lxd4 Sd5+ 12.Ke6+ Sf6 13.Lxf6# 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 54/24   00:00:30  6332kN
Also Lc0 with BT4- net solves almost at once, regards
Last edited by peter on Wed Jul 31, 2024 11:32 pm, edited 4 times in total.
Peter.
Top
MMarco
Posts: 211
Joined: Sun Apr 12, 2020 1:09 am
Full name: Marc-O Moisan-Plante

Re: Mate in 12, but impossible ...

Post by MMarco »

I see. Interestingly "Chess-System-Tal-2.00-v21-E1162-130-EAS.opt-avx2" also gets it quickly on one thread:

Code: Select all

n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - 0 1

Analysis by Chess-System-Tal-2.00-v21-E1162-130-EAS.opt-avx2:

1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Fxa5 Dg6+ 5.Rf4 Dh6+ 6.Re5 De3+ 7.De4+ Dxe4+ 8.Rxe4 
  Petit avantage blanc: = (0.27)  Profondeur: 10/20   00:00:00
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Fxa5 Dg6+ 5.Rf4 Dh6+ 6.Re5 De3+ 7.De4+ Dxe4+ 8.Rxe4 
  La position est équilibrée: = (0.17 ++)  Profondeur: 11/22   00:00:00
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Fxa5 De3+ 5.Rf5 Df2+ 6.Rg4 Dg1+ 7.Rh3 De3+ 8.Rg4 
  La position est équilibrée: = (0.00)  Profondeur: 11/28   00:00:00
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Fxa5 De3+ 5.Rf5 Df2+ 6.Rg4 Dg1+ 7.Rh3 De3+ 8.Rg4 
  La position est équilibrée: = (0.10 ++)  Profondeur: 12/28   00:00:00
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg7 5.Da1+ Rg8 6.Dd4 Rh7 7.Rf4 
  La position est équilibrée: = (0.01)  Profondeur: 12/28   00:00:00
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg7 5.Da1+ Rg8 6.Dd4 Rh7 7.Rf4 
  La position est équilibrée: = (0.12 ++)  Profondeur: 13/28   00:00:00  62kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 13/28   00:00:00  65kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 14/28   00:00:00  78kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 15/28   00:00:00  97kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 16/28   00:00:00  105kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 17/28   00:00:00  115kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 18/28   00:00:00  142kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 19/28   00:00:00  156kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 20/29   00:00:00  228kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 21/31   00:00:00  322kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 22/31   00:00:00  383kN
1.gxh7+ Rh8 2.Dxa8 De6+ 3.Rg5 Rxh7 4.Dh1+ Rg8 5.Ff6 De3+ 6.Rh5 De2+ 7.Rh6 De3+ 
  La position est équilibrée: = (0.00)  Profondeur: 23/31   00:00:00  444kN
1.Fc7 
  La position est équilibrée: = (0.10 ++)  Profondeur: 23/33   00:00:00  472kN
1.Fc7 
  La position est équilibrée: = (0.20 ++)  Profondeur: 23/33   00:00:00  480kN
1.Fc7 
  Les Blancs sont un peu mieux: +/= (0.35 ++)  Profondeur: 23/33   00:00:00  483kN
1.Fc7 
  Les Blancs sont un peu mieux: +/= (0.58 ++)  Profondeur: 23/33   00:00:00  488kN
1.Fc7 
  Les Blancs sont mieux: +/- (0.92 ++)  Profondeur: 23/33   00:00:00  493kN
1.Fc7 
  Les Blancs sont nettement mieux: +/- (1.43 ++)  Profondeur: 23/33   00:00:00  497kN
1.Fc7 
  Les Blancs sont nettement mieux: +- (2.20 ++)  Profondeur: 23/33   00:00:00  500kN
1.Fc7 
  Les Blancs ont un avantage décisif: +- (3.35 ++)  Profondeur: 23/33   00:00:00  505kN
1.Fc7 
  Les Blancs sont clairement gagnants: +- (5.06 ++)  Profondeur: 23/33   00:00:00  508kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 23/33   00:00:00  513kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 24/24   00:00:00  516kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 25/25   00:00:00  519kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 26/26   00:00:00  521kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 27/27   00:00:00  524kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 28/28   00:00:00  528kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 29/29   00:00:00  532kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 30/30   00:00:00  537kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 31/31   00:00:00  542kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 32/32   00:00:00  552kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 33/33   00:00:00  559kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 34/34   00:00:00  565kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 35/35   00:00:00  572kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 36/36   00:00:00  581kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 37/37   00:00:00  589kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 38/38   00:00:00  598kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 39/39   00:00:00  608kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 40/40   00:00:00  620kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 41/41   00:00:00  630kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 42/42   00:00:00  642kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 43/43   00:00:00  659kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 44/44   00:00:00  672kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 45/45   00:00:00  695kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 46/46   00:00:01  721kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 47/47   00:00:01  734kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 48/48   00:00:01  754kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 49/49   00:00:01  776kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 50/50   00:00:01  795kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 51/51   00:00:01  835kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 52/52   00:00:01  874kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 53/53   00:00:01  900kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 54/54   00:00:01  931kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 55/55   00:00:01  2223kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 56/56   00:00:01  2247kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 57/57   00:00:01  2291kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 58/58   00:00:01  2336kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 59/59   00:00:01  2377kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 60/60   00:00:01  2446kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 61/61   00:00:01  2524kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 62/62   00:00:01  2569kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 63/63   00:00:01  2643kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 64/64   00:00:01  2736kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 65/65   00:00:01  2803kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 66/66   00:00:01  2876kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 67/67   00:00:01  2976kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 68/68   00:00:02  3232kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 69/69   00:00:02  3391kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 70/70   00:00:02  3545kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 71/71   00:00:02  3861kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 72/72   00:00:02  4492kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 73/73   00:00:02  5131kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 74/74   00:00:02  5371kN
1.Fc7 Dxc8 2.gxf7+ Rh8 3.Fe5 Dc5 4.Fb2 Cc7 5.Fa1 a4 6.Fb2 a3 7.Fa1 a2 8.Fb2 a1D 9.Fxa1 Cd5+ 10.Re6+ Cc3 11.Fxc3+ Dxc3 12.f8D# 
  Les Blancs font mat: +- (#12)  Profondeur: 75/75   00:00:02  5714kN

(,  31.07.2024)
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chrisw
Posts: 4585
Joined: Tue Apr 03, 2012 4:28 pm
Location: Midi-Pyrénées
Full name: Christopher Whittington

Re: Mate in 12, but impossible ...

Post by chrisw »

peter wrote: ↑Wed Jul 31, 2024 11:03 pm It's a position derived from a Matous- study with first move cut off:
[pgn][Event "1.hm Szachy#0645"]
[Site "?"]
[Date "1975.??.??"]
[Round "?"]
[White "Matous=M"]
[Black "(+4013.13f6f8) (v)"]
[Result "1-0"]
[SetUp "1"]
[FEN "n2Bqk2/5p1p/5KP1/p7/6Q1/8/8/8 w - - 0 1"]
[PlyCount "25"]
[EventDate "1975.??.??"]

{Szachy=12(348) Szachy/12.} 1. Qc8 $1 (1. g7+ $2 Kg8) 1... Kg8 (1... Qe6+ 2. Qxe6 fxe6 3. gxh7) (1... Nc7 2. Be7+ Kg8 3. gxf7+) 2. Bc7 $1 Qxc8 (2... Nxc7 3. gxf7+) 3. gxf7+ Kh8 (3... Kf8 4. Bd6#) 4. Be5 $1 Qc5 $1 5. Bb2 $1 (5. Ba1 $2 Nc7 6. Bb2 a4 7. Ba1 a3) 5... Nc7 $1 6. Ba1 a4 7. Bb2 a3 8. Ba1 a2 9. Bb2 a1=Q 10. Bxa1 Nb5 11. Ke6+ Nc3 12. Bxc3+ Qxc3 13. f8=Q# 1-0
[/pgn]
n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - 0 1

Analysis by Dragon 3.3 by Komodo Chess 64-bit single thread (3.5GHz) 1G hash, Use Syzygy false:

Code: Select all

2.Dxa8 
  Die Stellung ist ausgeglichen.  
  = (-0.09)  Tiefe: 1   00:00:03  6Knoten
...
2.gxh7+ Kh8 3.Dxa8 De6+ 4.Kg5 Dg6+ 5.Kf4 Dd6+ 6.Ke3 Dc5+ 7.Ke2 Dc2+ 8.Ke3 
  Die Stellung ist ausgeglichen.  
  = (0.05)  Tiefe: 7   00:00:03  4416Knoten
2.Lc7 a4 
  Die Stellung ist ausgeglichen.  
  = (0.10 ++)  Tiefe: 7   00:00:03  4730Knoten
...
2.Lc7 Dxc8 3.gxf7+ 
  Weiß steht deutlich besser.  
  +- (1.73 ++)  Tiefe: 7   00:00:03  4975Knoten
...
2.Lc7 Sxc7 3.gxf7+ Kf8 4.fxe8D+ Sxe8+ 5.Ke6 h5 6.Dc5+ Kg8 7.Dc4 Sg7+ 8.Ke7+ Kh7 9.Dc2+ Kh8 10.Db2 Kg8 
  Weiß steht klar auf Gewinn.  
  +- (8.52 ++)  Tiefe: 17   00:00:04  283kN
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 17   00:00:04  293kN
...
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 Sd5+ 11.Ke6+ Sc3 12.Lxc3+ Dxc3 13.f8D# 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 40   00:00:10  3984kN
n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - - 0 1
Analysis by CorChess 4 dev-20240712-5bab62d7 single thread, (3.5GHz), 1G hash, Syzygy ProbeLimit 0:

Code: Select all

 
2.gxf7+ Dxf7+ 3.Ke5 De8+ 4.Kd4 Sb6 5.Dg4+ Kf8 6.Df5+ Df7 7.Dxf7+ Kxf7 8.Lxb6 
  Die Stellung ist ausgeglichen.  
  = (0.07)  Tiefe: 10/15   00:00:00
...
2.gxh7+ Kh8 3.Dxa8 De6+ 4.Kg5 De5+ 5.Kh6 Dg7+ 6.Kh5 Dg6+ 7.Kh4 Dh6+ 8.Kg4 De6+ 9.Kf3 Df5+ 10.Ke3 De5+ 11.Kd3 Dd6+ 12.Kc4 Db4+ 13.Kd5 Dd2+ 14.Kc5 Db4+ 
  Die Stellung ist ausgeglichen.  
  = (0.00)  Tiefe: 35/27   00:00:18  2653kN
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 Dd4+ 11.Lxd4 Sd5+ 12.Ke6+ Sf6 13.Lxf6# 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 36/28   00:00:21  3306kN
...
2.Lc7 Dxc8 3.gxf7+ Kh8 4.Le5 Dc5 5.Lb2 Sc7 6.La1 a4 7.Lb2 a3 8.La1 a2 9.Lb2 a1D 10.Lxa1 Dd4+ 11.Lxd4 Sd5+ 12.Ke6+ Sf6 13.Lxf6# 
  Weiß setzt Matt.  
  +- (#12)  Tiefe: 54/24   00:00:30  6332kN
Also Lc0 with BT4- net solves almost at once, regards
I guess then we can infer that SF(16?) is still not full width at the root even at nominal depth 70 (or even at depth 99, if the Agadmator report is correct).
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peter
Posts: 3276
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: Mate in 12, but impossible ...

Post by peter »

chrisw wrote: ↑Wed Jul 31, 2024 11:22 pm I guess then we can infer that SF(16?) is still not full width at the root even at nominal depth 70 (or even at depth 99, if the Agadmator report is correct).
Too much pruning of non-primaries, as it seems, differing to ShashChess, CorChess and Crystal as shown.
Here's SF 16.1 multithreaded (300Mn/s) with MultiPV=2:

n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - -

Engine: Chessify Cloud StockfishS (0 MB)
von Chessify, Inc.

58 0:12 +M12 1.Lc7 Dxc8 2.gxf7+ Kh8 3.Le5 Dc5
4.Lb2 Sc7 5.La1 a4 6.Lb2 a3 7.La1 a2
8.Lb2 a1D 9.Lxa1 Dd4+ 10.Lxd4 Sd5+
11.Kf5+ Sf6 12.Lxf6+ (4.440.099.255) 351607

57 0:12 0.00 1.gxh7+ Kh8 2.Dxa8 De6+ 3.Kg5 Dg6+
4.Kf4 Dd6+ 5.Kg4 Dg6+ 6.Lg5+ Kxh7
7.Dxa5 De4+ 8.Lf4 Dg2+ 9.Lg3 De2+
10.Kg5 De3+ 11.Lf4 Dg1+ 12.Kh4 Dh1+
13.Kg3 Dg1+ (4.440.099.255) 351607
Peter.
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peter
Posts: 3276
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: Mate in 12, but impossible ...

Post by peter »

And again single thread (3.5GHz) 1G hash, Syzygy ProbeLimit 0, MultiPV=6:

n1QBq1k1/5p1p/5KP1/p7/8/8/8/8 w - -

Engine: Stockfish dev-20240709-362a77a30 (1024 MB)
von the Stockfish developers (see AUTHORS f

Code: Select all

...

24/44  0:03   +M12     1.Lc7 Dxc8 2.gxf7+ Kh8 3.Le5 Dc5 
                       4.Lb2 Sc7 5.La1 a4 6.Lb2 a3 7.La1 a2 
                       8.Lb2 a1D 9.Lxa1 De5+ 10.Lxe5 Sd5+ 
                       11.Ke6+ Sf6 12.Lxf6+ (5.334.796) 1406 

24/32  0:03   0.00     1.gxh7+ Kh8 2.Dxa8 De6+ 3.Kg5 De5+ 
                       4.Kh6 Dg7+ 5.Kh5 Dg6+ 6.Kh4 Kxh7 
                       7.Dxa5 De4+ 8.Kg3 Dd3+ 9.Kg2 De2+ 
                       10.Kg1 Dd1+ 11.Kf2 Dd4+ 12.Ke2 Dg4+ 
                       13.Kf2 (5.334.796) 1406 

24/32  0:03   0.00     1.Dxa8 De6+ 2.Kg5 Kg7 3.gxh7 De5+ 
                       4.Kh4 Kxh7 5.Df3 Kg7 6.Dg2+ Kf8 
                       7.Dd2 Kg8 8.Dg2+ Kh7 (5.334.796) 1406 

24/39  0:03   -0.09    1.gxf7+ Dxf7+ 2.Kg5 Dd5+ 3.Kf6 Dd6+ 
                       4.Kg5 Kf7 5.Dc4+ De6 6.Dxe6+ Kxe6 
                       7.Lxa5 Sb6 8.Kh6 Sd5 9.Kxh7 Sf6+ 
                       10.Kg7 Se8+ 11.Kh7 Sd6 (5.334.796) 1406 

24/32  0:03   -0.24    1.Kg5 hxg6 2.Dxa8 a4 3.Kf4 Df8 4.Db8 a3 
                       5.Db6 a2 6.Lf6 a1D 7.Lxa1 Dh6+ 8.Kg4 Dh5+ 
                       9.Kg3 Dg5+ 10.Kf3 Dd5+ 11.Kg3 Dd3+ 
                       12.Kg2 De4+ 13.Kf2 Df4+ 14.Kg2 (5.334.796) 1406 

24/37  0:03   -0.34    1.Db8 hxg6 2.Dxa8 a4 3.Dd5 De6+ 
                       4.Dxe6 fxe6 5.Le7 Kh7 6.Lf8 e5 
                       7.Kxe5 Kg8 8.La3 g5 9.Kf5 Kf7 
                       10.Kxg5 Ke6 11.Kf4 Kd5 12.Kf3 (5.334.796) 1406
Peter.
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User avatar
Rebel
Posts: 7254
Joined: Thu Aug 18, 2011 12:04 pm
Full name: Ed Schröder

Re: Mate in 12, but impossible ...

Post by Rebel »

chrisw wrote: ↑Wed Jul 31, 2024 10:43 pm
Is Crystal a matefinder, because obviously matefinders will find mates. What's interesting is what prevents (allegedly) the SF-model from finding a M12 with 70 plies of nominal search. Give SF the first move and the solution is almost immediate.
Ah, the notorious null move zugzwang.

Both Cstal an Rebel within less of a second here.

Code: Select all

 25/39	00:00	 1.191k	1.360k	 0,00	g6xh7+ Kg8-h8 Qc8-c3 Qe8-e6+ Kf6-g5+ Kh8xh7 Qc3xa5 Kh7-g8 Kg5-f4 f7-f5 Qa5xa8 Qe6-e4+ Qa8xe4 f5xe4 Kf4xe4
 25/39+	00:00	 1.240k	1.359k	+0,10	Bd8-c7
 25/25+	00:00	 1.286k	1.368k	+5,06	Bd8-c7
 25/28	00:00	 1.351k	1.406k	+M13	Bd8-c7 Qe8xc8 g6xf7+ Kg8-h8 Bc7-e5 Qc8-c5 Be5-b2 Na8-c7 Bb2-a1 a5-a4 Ba1-b2 a4-a3 Bb2-a1 a3-a2 Ba1-b2 a2-a1Q Bb2xa1 Qc5-d6+ Kf6-f5+ Qd6-f6+ Kf5xf6 h7-h6 f7-f8Q+ Kh8-h7 Qf8-g7+
 26/26	00:00	 1.356k	1.407k	+M12	Bd8-c7 Qe8xc8 g6xf7+ Kg8-h8 Bc7-e5 Qc8-c5 Be5-b2 Na8-c7 Bb2-a1 a5-a4 Ba1-b2 a4-a3 Bb2-a1 a3-a2 Ba1-b2 a2-a1Q Bb2xa1 Nc7-d5+ Kf6-e6+ Nd5-c3 Ba1xc3+ Qc5xc3 f7-f8Q+
90% of coding is debugging, the other 10% is writing bugs.
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