Start Your Engines

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Paloma
Posts: 1167
Joined: Thu Dec 25, 2008 9:07 pm
Full name: Herbert L

Re: Start Your Engines

Post by Paloma »

:idea: :idea: :idea: NO NO No No :) :) :)
zullil wrote:
zullil wrote:Cfish feels it's Mate-in-26 (not 27 as I submitted originally). Here's what I can offer:

Code: Select all

Mate in 26  1. Rc8+ Kb7 2. Bg2+ Kxb6 3. Rxa8 Bf6+ 4. Kc4 Be5 5. Kd5 Bf6 6. Rf8 Ba1 7. Rf7 a5 8. Rxd7 a4 9. Bf1 a3 10. Rd6+ Kb7 11. Rc6 Bf6 12. Ba6+ Ka7 13. Bc4 Kb7 14. Kd6 Be5+ 15. Kd7 Bd4 16. Bd5 Ka7 17. Re6 a2 18. Bxa2 Bb6 19. Kc6 Ka6 20. Re4 Ka5 21. Bb3 Ka6 22. Bc4+ Ka7 23. Re7+ Bc7 24. Kxc7 Ka8 25. Re5 g5 26. Ra5# (depth 112)
I'll keep the search running, and the hash table full, for a bit more, in case anyone wants to explore options.
[pgn]
[Result "1-0"]
[FEN "rk1b4/p2p2p1/1P6/2R2P2/8/2K5/8/5B2 w - - 0 1"]
[SetUp "1"]
1. Rc8+ Kb7 2. Bg2+ Kxb6 3. Rxa8 Bf6+ 4. Kc4 Be5 5. Kd5 Bf6 6. Rf8 Ba1 7.
Rf7 a5 8. Rxd7 a4 9. Bf1 a3 10. Rd6+ Kb7 11. Rc6 Bf6 12. Ba6+ Ka7 13. Bc4
Kb7 14. Kd6 Be5+ 15. Kd7 Bd4 16. Bd5 Ka7 17. Re6 a2 18. Bxa2 Bb6 19. Kc6
Ka6 20. Re4 Ka5 21. Bb3 Ka6 22. Bc4+ Ka7 23. Re7+ Bc7 24. Kxc7 Ka8 25. Re5
g5 26. Ra5#
{White mates} 1-0
[/pgn]
Going your Line backwards i found 6... Ba1 (?) leads to mate in 26

4... Be5 {L.Zulli} 5.Kd5 Bf6 6. Rf8 Ba1 ? :?:
7. Rf7 {20#} a5 8. Rxd7 {19#} a4 9. Bf1 a3 10. Rd6+ Kb7 11. Rc6 Bf6 12. Ba6+ Ka7 13. Bc4 Kb7 14. Kd6 Be5+ 15. Kd7 Bd4 16. Bd5 Ka7 17. Re6 a2 18. Bxa2 Bb6 19. Kc6 Ka6 20. Re4 Ka5 21. Bb3 Ka6 22. Bc4+ Ka7 23. Re7+ Bc7 24. Kxc7 Ka8 25. Re5 g5 26. Ra5#

better is 6... Bc3 which leads to mate in 27 !! :!:

(6... Bc3 ! 7. Rf7 {21#} Kc7 8. Bf1 Bb2 9. Bb5 Kb6 10. Rxd7 Bf6 11. Bc6 a6 12. Rb7+ Ka5 13. Kc5 Bg5 14. Kc4 Bd2 15. Rxg7 Bf4 16. f6 Bd6 17. Rb7 Bf8 18. Bg2 Bb4 19. f7 Bf8 20. Rb8 Bh6 21. f8=Q Bxf8 22. Rxf8 Kb6 23. Rf7 a5 24. Rb7+ Ka6 25. Kc5 a4 26. Rb8 a3 27. Ra8#)

(Stockfish Matefinder)
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zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Start Your Engines

Post by zullil »

Paloma wrote:NO.
To L.Zulli:

Going your Line backwards i found 6... Ba1 (?) leads to mate in 26

4... Be5 {L.Zulli} 5.Kd5 Bf6 6. Rf8 Ba1 ?
7. Rf7 {20#} a5 8. Rxd7 {19#} a4 9. Bf1 a3 10. Rd6+ Kb7 11. Rc6 Bf6 12. Ba6+ Ka7 13. Bc4 Kb7 14. Kd6 Be5+ 15. Kd7 Bd4 16. Bd5 Ka7 17. Re6 a2 18. Bxa2 Bb6 19. Kc6 Ka6 20. Re4 Ka5 21. Bb3 Ka6 22. Bc4+ Ka7 23. Re7+ Bc7 24. Kxc7 Ka8 25. Re5 g5 26. Ra5#

better is 6... Bc3 which leads to mate in 27 !!

(6... Bc3 ! 7. Rf7 {21#} Kc7 8. Bf1 Bb2 9. Bb5 Kb6 10. Rxd7 Bf6 11. Bc6 a6 12. Rb7+ Ka5 13. Kc5 Bg5 14. Kc4 Bd2 15. Rxg7 Bf4 16. f6 Bd6 17. Rb7 Bf8 18. Bg2 Bb4 19. f7 Bf8 20. Rb8 Bh6 21. f8=Q Bxf8 22. Rxf8 Kb6 23. Rf7 a5 24. Rb7+ Ka6 25. Kc5 a4 26. Rb8 a3 27. Ra8#)
Well, maybe my submitted answer was correct after all. Will investigate this later, when I'm done with work!
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zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Start Your Engines

Post by zullil »

Paloma wrote::idea: :idea: :idea: NO NO No No :) :) :)
zullil wrote:
zullil wrote:Cfish feels it's Mate-in-26 (not 27 as I submitted originally). Here's what I can offer:

Code: Select all

Mate in 26  1. Rc8+ Kb7 2. Bg2+ Kxb6 3. Rxa8 Bf6+ 4. Kc4 Be5 5. Kd5 Bf6 6. Rf8 Ba1 7. Rf7 a5 8. Rxd7 a4 9. Bf1 a3 10. Rd6+ Kb7 11. Rc6 Bf6 12. Ba6+ Ka7 13. Bc4 Kb7 14. Kd6 Be5+ 15. Kd7 Bd4 16. Bd5 Ka7 17. Re6 a2 18. Bxa2 Bb6 19. Kc6 Ka6 20. Re4 Ka5 21. Bb3 Ka6 22. Bc4+ Ka7 23. Re7+ Bc7 24. Kxc7 Ka8 25. Re5 g5 26. Ra5# (depth 112)
I'll keep the search running, and the hash table full, for a bit more, in case anyone wants to explore options.
[pgn]
[Result "1-0"]
[FEN "rk1b4/p2p2p1/1P6/2R2P2/8/2K5/8/5B2 w - - 0 1"]
[SetUp "1"]
1. Rc8+ Kb7 2. Bg2+ Kxb6 3. Rxa8 Bf6+ 4. Kc4 Be5 5. Kd5 Bf6 6. Rf8 Ba1 7.
Rf7 a5 8. Rxd7 a4 9. Bf1 a3 10. Rd6+ Kb7 11. Rc6 Bf6 12. Ba6+ Ka7 13. Bc4
Kb7 14. Kd6 Be5+ 15. Kd7 Bd4 16. Bd5 Ka7 17. Re6 a2 18. Bxa2 Bb6 19. Kc6
Ka6 20. Re4 Ka5 21. Bb3 Ka6 22. Bc4+ Ka7 23. Re7+ Bc7 24. Kxc7 Ka8 25. Re5
g5 26. Ra5#
{White mates} 1-0
[/pgn]
Going your Line backwards i found 6... Ba1 (?) leads to mate in 26

4... Be5 {L.Zulli} 5.Kd5 Bf6 6. Rf8 Ba1 ? :?:
7. Rf7 {20#} a5 8. Rxd7 {19#} a4 9. Bf1 a3 10. Rd6+ Kb7 11. Rc6 Bf6 12. Ba6+ Ka7 13. Bc4 Kb7 14. Kd6 Be5+ 15. Kd7 Bd4 16. Bd5 Ka7 17. Re6 a2 18. Bxa2 Bb6 19. Kc6 Ka6 20. Re4 Ka5 21. Bb3 Ka6 22. Bc4+ Ka7 23. Re7+ Bc7 24. Kxc7 Ka8 25. Re5 g5 26. Ra5#

better is 6... Bc3 which leads to mate in 27 !! :!:

(6... Bc3 ! 7. Rf7 {21#} Kc7 8. Bf1 Bb2 9. Bb5 Kb6 10. Rxd7 Bf6 11. Bc6 a6 12. Rb7+ Ka5 13. Kc5 Bg5 14. Kc4 Bd2 15. Rxg7 Bf4 16. f6 Bd6 17. Rb7 Bf8 18. Bg2 Bb4 19. f7 Bf8 20. Rb8 Bh6 21. f8=Q Bxf8 22. Rxf8 Kb6 23. Rf7 a5 24. Rb7+ Ka6 25. Kc5 a4 26. Rb8 a3 27. Ra8#)

(Stockfish Matefinder)
Is 11. Bc6 optimal? What about 11. Bd3?
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Paloma
Posts: 1167
Joined: Thu Dec 25, 2008 9:07 pm
Full name: Herbert L

Re: Start Your Engines

Post by Paloma »

8/p2R2p1/1k3b2/1B1K1P2/8/8/8/8 w - - 0 1

Analysis by Stockfish MateFinder 64 BMI2 Ellis1117:

1. +- (#17): 11.Bc6 a6 12.Rb7+ Ka5 13.Kc5 Bh4 14.Rxg7 Bf6 15.Rb7 Bb2 16.Kc4 Bh8 17.Bg2 Ba1 18.Rb8 Bf6 19.Rc8 Bg5 20.Rc6 Bd2 21.f6 Ka4 22.Rxa6+ Ba5 23.Be4 Ka3 24.Rxa5+ Kb2 25.Bd3 Kc1 26.Kc3 Kd1 27.Ra1#
2. +- (#18): 11.Ba4 Ka5 12.Rxa7+ Kb4 13.Rf7 Bd8 14.Rxg7 Kxa4 15.Rg8 Bf6 16.Rg6 Bd8 17.Kc4 Ka3 18.Ra6+ Kb2 19.f6 Kc2 20.Re6 Bxf6 21.Rxf6 Kd2 22.Re6 Kc2 23.Re2+ Kd1 24.Kd3 Kc1 25.Kc3 Kb1 26.Re1+ Ka2 27.Rd1 Ka3 28.Ra1#
White mates

(depth 50)
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Ovyron
Posts: 4556
Joined: Tue Jul 03, 2007 4:30 am

Re: Start Your Engines

Post by Ovyron »

zullil wrote:
Rebel wrote:Which would mean, provided M26 is correct, nobody had it right :lol:
Which engines even find Rc8+ on their own, i.e., without launching a browser and Googling the FEN? :wink:
Houdini 6 with Contempt=2 doesn't even consider anything else.
Your beliefs create your reality, so be careful what you wish for.
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Paloma
Posts: 1167
Joined: Thu Dec 25, 2008 9:07 pm
Full name: Herbert L

Re: Start Your Engines

Post by Paloma »

11.Bd3

11...Ka5 12.Kc5 a6 13.Bc2 Bg5 14.Rxg7 Be3+ 15.Kc4 Kb6 16.Be4 Bc1 17.Rb7+ Ka5 18.f6 Bh6 19.f7 Bf8 20.Rb8 Ba3 21.f8Q Bxf8 22.Rxf8 Kb6 23.Rf7 a5 24.Rb7+ Ka6 25.Kc5 a4 26.Rb8 a3 27.Ra8#
White mates: +- (#16) Tiefe: 48/33 00:39:38 23187MN, tb=1170731159
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Spliffjiffer
Posts: 416
Joined: Thu Aug 02, 2012 7:48 pm
Location: Germany

Re: Start Your Engines

Post by Spliffjiffer »

its a bit early to say that Louis line in 26 moves is wrong !!...but...

1. Herbert, i might be wrong but i would recommend you to disable TB-access to find quickest mates in such positions (assuming ure using sysygy and not nalimov TB's) !!?...ure claiming that 6...bc3 !? is superior to 6...ba1 and according to my own analysis 6...bc3 is the only move for black !?, thank you very much :-)...after 8...bb2? its a mate in 18 (26 moves in the end)...after 11.bd3 Ka5?? (11...a5 is correct, mate in 15) 12. Kc4 its even a mate in 14 (25 moves in the end)

2.the only move for black that might (or might not) prolong the mate to 27 moves in the end is 8...ba1 !!? after which im still not able to replicate Louis analysis:
[d]8/p1kp1Rp1/8/3K1P2/8/8/8/b4B2 w - - 11 9
is there a mate in 18 moves ??
Wahrheiten sind Illusionen von denen wir aber vergessen haben dass sie welche sind.
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zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Start Your Engines

Post by zullil »

Spliffjiffer wrote:its a bit early to say that Louis line in 26 moves is wrong !!...but...

1. Herbert, i might be wrong but i would recommend you to disable TB-access to find quickest mates in such positions (assuming ure using sysygy and not nalimov TB's) !!?...ure claiming that 6...bc3 !? is superior to 6...ba1 and according to my own analysis 6...bc3 is the only move for black !?, thank you very much :-)...after 8...bb2? its a mate in 18 (26 moves in the end)...after 11.bd3 Ka5?? (11...a5 is correct, mate in 15) 12. Kc4 its even a mate in 14 (25 moves in the end)

2.the only move for black that might (or might not) prolong the mate to 27 moves in the end is 8...ba1 !!? after which im still not able to replicate Louis analysis:
[d]8/p1kp1Rp1/8/3K1P2/8/8/8/b4B2 w - - 11 9
is there a mate in 18 moves ??
Cfish suggests:

Code: Select all

Mate in 18  9. Bb5 Kb6 10. Bxd7 a6 11. Re7 Bf6 12. Re6+ Kc7 13. Ba4 Kb7 14. Rc6 Bg5 15. Kd6 Be3 16. Kd7 Bd4 17. Bd1 a5 18. Bf3 Ka7 19. Kc7 Be5+ 20. Kc8 Bd4 21. Be2 Bb6 22. Rg6 a4 23. Rxg7+ Bc7 24. Kxc7 a3 25. Rg4 a2 26. Ra4# (depth 80, 0:02:55)
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Spliffjiffer
Posts: 416
Joined: Thu Aug 02, 2012 7:48 pm
Location: Germany

Re: Start Your Engines

Post by Spliffjiffer »

thanks Louis...your line is correct !!...ill investigate further backwards :-)
Wahrheiten sind Illusionen von denen wir aber vergessen haben dass sie welche sind.
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zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Start Your Engines

Post by zullil »

Ovyron wrote:
zullil wrote:
Rebel wrote:Which would mean, provided M26 is correct, nobody had it right :lol:
Which engines even find Rc8+ on their own, i.e., without launching a browser and Googling the FEN? :wink:
Houdini 6 with Contempt=2 doesn't even consider anything else.
Sounds like a bug. :twisted:
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