Shocking misevaluation by SF

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Lyudmil Tsvetkov
Posts: 6052
Joined: Tue Jun 12, 2012 12:41 pm

Re: PGN Re: Shocking misevaluation by SF

Post by Lyudmil Tsvetkov »

Spliffjiffer wrote:dear Lyudmil...in my opinion ure not willing to analyse sth in depth at any point :-(...if u had spend 1 sec to analyse what ure talking about with 20. rf4 u would get it...how to say best for u?...hm..ok, 20. rf4 looses to rd4.
oops, difficult to see at first glance.

I don't know why you should be angry.

mistakes happen, just explain.

I did not follow the whole line, maybe you are right black is winning, but I don't know that, as I did not check.
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Spliffjiffer
Posts: 416
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Location: Germany

Re: PGN Re: Shocking misevaluation by SF

Post by Spliffjiffer »

[d]8/8/4k1p1/7p/5RnP/6P1/1r3PK1/8 b - - 0 5

for example:
5. ... Ne5 6. Rf8 Ke7 7. Ra8 Ng4 8. Ra7+ Kf6 9. Ra6+ Kf5 10. Ra5+ Ke4 11.
Ra4+ Kd3 12. Ra3+ Ke2 13. Ra6 Rd2 -+

im not angry Lyudmil, im happy :-)
Wahrheiten sind Illusionen von denen wir aber vergessen haben dass sie welche sind.
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Lyudmil Tsvetkov
Posts: 6052
Joined: Tue Jun 12, 2012 12:41 pm

Re: PGN Re: Shocking misevaluation by SF

Post by Lyudmil Tsvetkov »

Spliffjiffer wrote:[d]8/8/4k1p1/7p/5RnP/6P1/1r3PK1/8 b - - 0 5

for example:
5. ... Ne5 6. Rf8 Ke7 7. Ra8 Ng4 8. Ra7+ Kf6 9. Ra6+ Kf5 10. Ra5+ Ke4 11.
Ra4+ Kd3 12. Ra3+ Ke2 13. Ra6 Rd2 -+

im not angry Lyudmil, im happy :-)
and if 6.Kg1?
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Spliffjiffer
Posts: 416
Joined: Thu Aug 02, 2012 7:48 pm
Location: Germany

Re: PGN Re: Shocking misevaluation by SF

Post by Spliffjiffer »

i think rd2 is best...whats your move after that?
Wahrheiten sind Illusionen von denen wir aber vergessen haben dass sie welche sind.
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Lyudmil Tsvetkov
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Joined: Tue Jun 12, 2012 12:41 pm

Re: PGN Re: Shocking misevaluation by SF

Post by Lyudmil Tsvetkov »

Spliffjiffer wrote:i think rd2 is best...whats your move after that?
20 games shootout with SF and Komodo: 6 black wins, 14 draws

judging by this result in a fairly simple endgame, I would say this is more likely a draw, unless some very strong black moves exist.

I really don't believe black can win that, as said, no possibility for zugzwang, white king can move to f1,g1,g2, white rook to another couple of squares, so I guess losses are due to some made-up positions, but I might be wrong, did not look closely.

my problem is I don't know where this position comes from, is it a result of best play from both sides, etc.

in order to win, black should create some tactics, like your Rd4, but I don't see how this is possible to do with best play, as said, white simply has too many options.

tomorrow maybe more.
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Spliffjiffer
Posts: 416
Joined: Thu Aug 02, 2012 7:48 pm
Location: Germany

Re: PGN Re: Shocking misevaluation by SF

Post by Spliffjiffer »

well the easiest way to see wether you or i am wrong is to study my mainlines i have given...there are many hours of work in em...im sure they are correct but mybe youre right and its a draw indeed...as you mentioned you are not particularly interested in that, so i think the confirmation/refutation of my "win-claim" comes from so else if it comes to that :-)

regards, Peer
Wahrheiten sind Illusionen von denen wir aber vergessen haben dass sie welche sind.
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Lyudmil Tsvetkov
Posts: 6052
Joined: Tue Jun 12, 2012 12:41 pm

Re: PGN Re: Shocking misevaluation by SF

Post by Lyudmil Tsvetkov »

Spliffjiffer wrote:well the easiest way to see wether you or i am wrong is to study my mainlines i have given...there are many hours of work in em...im sure they are correct but mybe youre right and its a draw indeed...as you mentioned you are not particularly interested in that, so i think the confirmation/refutation of my "win-claim" comes from so else if it comes to that :-)

regards, Peer
I am very much interested in it, it is just the least interesting of 5 or 6 other positions I am analysing currently, so, when I finish with the other 5, I am back to this. :)

no one having 10-men tablebases installed?
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Eelco de Groot
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Re: Shocking misevaluation by SF

Post by Eelco de Groot »

Spliffjiffer wrote:for example i struggle mostly with this line atm:

1. Kg1 Rc2 2. Ra6 Ke4 3. Ra4+ Rc4 4. Ra8
[d]R7/8/6p1/4n2p/2r1k2P/6P1/5P2/6K1 b - - 7 4
Maybe making some slight headway against 2. Ra6 (No backward solving involved this time. Three best Multi PV No changes in evaluation but a little bit in search. Instead of LMP I use LTP Lyudmil Tsvetkov Late Move Pruning 8-)) But it could be nothing. Can anybody maybe confirm (that Black is winning) Maybe we should try not just Stockfish here?

[D]8/8/5Rp1/3kn2p/7P/6P1/2r2P2/6K1 w - -

Engine: Ancalagon (_045) HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

43 33:30 -2.36 2.Ra6 Rd2 3.Ra5+ Ke4 4.Ra4+ Rd4
5.Ra8 Rb4 6.Ra6 Rb1+ 7.Kg2 Rb3
8.Ra4+ Kd3 9.Ra8 Ng4 10.Rd8+ Kc4
11.Rc8+ Kd5 12.Rd8+ Ke6 13.Re8+ Kd7
14.Re2 Kd6 15.Rc2 (32.327.254.263) 16082

43 33:30 -2.36 2.Rb6 Ke4 3.Rb4+ Kd3 4.Rb7 Ra2
5.Rb3+ Kc4 6.Rb7 Nd3 7.Rf7 Kd4 8.Rf6 Ne5
9.Kf1 Ng4 10.Rf4+ Ke5 11.Kg2 Rc2
12.Rf8 Kd6 13.Kg1 Ke7 14.Rf4 Re2
15.Rf3 (32.327.254.263) 16082

43 33:30 -2.36 2.Kg2 Rc6 3.Rf8 Ng4 4.Rf7 Rc2 5.Rf4 Ke5
6.Rf8 Kd4 7.Rd8+ Ke4 8.Re8+ Kf5
9.Rf8+ Ke5 10.Rf4 Rb2 11.Kg1 Ke6
12.Re4+ Kd7 13.Rd4+ Kc6 14.Rf4 Kc5
15.Kg2 (32.327.254.263) 16082
__________________________________________________________

44 41:40 -2.36 2.Ra6 Rd2 3.Ra5+ Ke4 4.Ra4+ Rd4
5.Ra5 Rb4 6.Ra6 Rb1+ 7.Kg2 Kd4
8.Ra4+ Kd5 9.Ra5+ Ke6 10.Ra6+ Kf5
11.Ra5 Rb2 12.Kf1 Ke6 13.Ra6+ Kd5
14.Ra5+ Kd4 15.Ra4+ (40.817.167.247) 16324

44 41:40 -2.36 2.Rb6 Ke4 3.Rb4+ Kd3 4.Rb3+ Kd4
5.Rb4+ Kc5 6.Rb8 Ra2 7.Rf8 Ra1+
8.Kg2 Kc4 9.Rc8+ Kd4 10.Rd8+ Ke4
11.Re8 Ra2 12.Rf8 Rb2 13.Rf4+ Kd5
14.Rf6 Ra2 15.Kg1 (40.817.167.247) 16324

44 41:40 -2.43 2.Kg2 Ng4 3.Rf3 Rb2 4.Rf4 Ke6 5.Rf8 Rc2
6.Rf4 Ke5 7.Rf8 Ra2 8.Re8+ Kd5 9.Rf8 Kc4
10.Rf3 Kd4 11.Rf7 Kc5 12.Rf4 Kd6
13.Kg1 Ke5 14.Kg2 Rd2 15.Rf8 (40.817.167.247) 16324
__________________________________________________________

45 60:08 -2.51 2.Ra6 Rb2 3.Ra5+ Ke6 4.Ra6+ Kf5
5.Ra5 Ke4 6.Ra4+ Kd3 7.Ra3+ Kd2
8.Re3 Ng4 9.Re8 Ra2 10.Kf1 Kd3
11.Rd8+ Kc4 12.Rc8+ Kd5 13.Rf8 Kd6
14.Kg1 Ke7 15.Rf4 (59.370.725.321) 16451

45 60:08 -2.51 2.Rb6 Ra2 3.Rf6 Kd4 4.Kg2 Ng4 5.Rf8 Re2
6.Rd8+ Kc4 7.Rc8+ Kd3 8.Rd8+ Kc3
9.Rf8 Rb2 10.Kf1 Kd4 11.Kg1 Ke5
12.Kg2 Ke6 13.Kg1 Ra2 14.Kg2 Ne5
15.Re8+ (59.370.725.321) 16451

45 60:08 -2.51 2.Kg2 Rb2 3.Kg1 Ra2 4.Kg2 Ng4 5.Rf8 Kc6
6.Kg1 Kd7 7.Rf4 Ke7 8.Kg2 Kd6 9.Rf8 Rc2
10.Rf3 Kd5 11.Rf4 Rb2 12.Rf3 Re2
13.Rf8 Kc5 14.Rf7 Kd6 15.Rf3 (59.370.725.321) 16451
__________________________________________________________

46 71:37 -2.58 2.Ra6 Rb2 3.Rf6 Kd4 4.Kg2 Ng4 5.Rf4+ Kd3
6.Kf1 Ra2 7.Rf3+ Ke4 8.Rf4+ Kd5
9.Kg2 Rb2 10.Rf7 Kd6 11.Rf3 Ke7
12.Rf4 Rc2 13.Kf1 Ne5 14.Re4 Kf6
15.Rf4+ (69.435.029.725) 16156

46 71:37 -2.58 2.Rb6 Ra2 3.Rb5+ Kd4 4.Rb4+ Kd3
5.Rb3+ Kd2 6.Re3 Ng4 7.Re8 Kd3 8.Rf8 Rb2
9.Rd8+ Kc4 10.Rf8 Kd4 11.Rd8+ Kc5
12.Rc8+ Kd5 13.Rd8+ Ke4 14.Re8+ Kf5
15.Rf8+ (69.435.029.725) 16156

46 71:37 -2.58 2.Kg2 Ng4 3.Rf4 Rb2 4.Rf8 Kc4 5.Kg1 Kc5
6.Kg2 Kd6 7.Kf1 Ra2 8.Rf4 Kd5 9.Kg2 Rd2
10.Kf1 Ke6 11.Kg2 Ra2 12.Re4+ Kf6
13.Kg1 Ne5 14.Re3 Rd2 15.Re4 (69.435.029.725) 16156

8-)
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
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Spliffjiffer
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Location: Germany

Re: Shocking misevaluation by SF

Post by Spliffjiffer »

i finished white after ...ra6 like this:

1. ... Ke4 2. Ra4+ Kd3 3. Ra3+ Kd2 4. Kf1 Ng4 5. Ra8 Kc3 6. Rc8+ Kd3 7.
Rd8+ Ke4 8. Re8+ Kf5 9. Rf8+ Ke6 10. Kg1 Ne5....
and we get to the mainline i gave before :-)

after i had found out that this wins like this i menaged to improve blacks play by not letting the rook to the a file where he wanna give me these annoing checks :-)...such as this:

1. ... Rb2+ 2. Kf1 Kd4 !(instead of kd5)3. Rd6+ Ke4 4. Rf6 Ng4...
the mainline for this i also gave before ;-)

for those who dont wanna search the mainline here it is again ( 2 variations) :

[d]8/8/5Rp1/2k1n2p/7P/1r4P1/4KP2/8 w - - 0 1

1. Kf1 Rb2 2. Kg1 Kd4 3. Rf4+ Kd3 4. Kf1 Ng4 5. Rf3+ Ke4 6. Rf4+ Ke5 7. Kg1 Rd2 8. Rf8 Ke6 9. Re8+ Kf7 10. Re4 Kg7 11. Re7+ Kf6 12. Re4 Ne5 13. Rf4+ Kg7 14. Re4 Nd3 15. Re7+ Kf6 16. Re8 Kf5 17. Rf8+ Ke6 18. Rf3 Rd1+ 19. Kh2 Ne5 20. Re3 Rd2 21. Kg1 Kd5 22. Ra3 Nd3 23. Ra8 Ke6 24. Re8+ Kf6 25. Rf8+ Kg7 26. Rf3 Rd1+ 27. Kh2 Ne5 28. Ra3 Rd2 29. Kg2 Nd3 30. Ra7+ Kf6 31. Ra6+ Kf5 32. Ra5+ Ke4 33. Ra4+ Kd5 34. Ra5+ Kd4 35. Ra4+ Kc3 36. Ra3+ Kc4 -+


1. Kf1 Rb2 2. Rf4 Ng4 3. Kg1 Kd6 4. Kf1 Ke6 5. Kg1 Ne5 6. Re4 Kf6 7. Re3
Rd2 8. Re4 Nd3 9. Re8 Kf5 10. Rf8+ Ke6 11. Rf3 Rd1+ 12. Kh2 Ne5 13. Re3 Rd2 14. Kg1 Kf6 15. Re4 Nd3 16. Re8 Kf5 17. Rf8+ Ke6 18. Rf3 Rd1+ 19. Kh2 Ne5 20. Re3 Rd2 21. Kg1 Kd5 22. Ra3 Nd3 23. Ra8 Ke6 24. Re8+ Kf6 25. Rf8+ Kg7 26. Rf3 Rd1+ 27. Kh2 Ne5 28. Ra3 Rd2 29. Kg2 Nd3 30. Ra7+ Kf6 31. Ra6+ Kf5 32. Ra5+ Ke4 33. Ra4+ Kd5 34. Ra5+ Kd4 35. Ra4+ Kc3 36. Ra3+ Kc4 -+

as white connot play 1. ra6?? because its loosing immediately it doesnt matter that the position is the wrong one because white cant do anything with the extra move ;-)
Wahrheiten sind Illusionen von denen wir aber vergessen haben dass sie welche sind.
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Eelco de Groot
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Re: Shocking misevaluation by SF

Post by Eelco de Groot »

Spliffjiffer wrote:i finished white after ...ra6 like this:

1. ... Ke4 2. Ra4+ Kd3 3. Ra3+ Kd2 4. Kf1 Ng4 5. Ra8 Kc3 6. Rc8+ Kd3 7.
Rd8+ Ke4 8. Re8+ Kf5 9. Rf8+ Ke6 10. Kg1 Ne5....
and we get to the mainline i gave before :-)
Hi Peer,

I have not made much progress trying to get stockfish to see anything without backsolving. I could go back to the final position after 28 moves in main line #1 but have not had time for that. Everything seemed to go well in the position where you end above line, although two moves put up much resistance, the rest seems to fall well below -3.00:

[D]5R2/8/4k1p1/4n2p/7P/6P1/2r2P2/6K1 w - -

Engine: Ancalagon_049 HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

40 253:40 -2.16 12.Rf4 Ra2 13.Rf8 Nd3 14.Rf3 Rd2
15.Kf1 Ke7 16.Kg1 Rd1+ 17.Kh2 Ke6
18.Re3+ Kd6 19.Rf3 Ne5 20.Rf4 Ke6
21.Kg2 Rd2 22.Re4 Kd5 23.Rf4 Rb2
24.Kg1 Ng4 25.Kg2 (259.363.693.512) 17040

40 253:40 -2.21 12.Re8+ Kd6 13.Rb8 Ke7 14.Rb7+ Ke6
15.Rb6+ Kf5 16.Rb5 Ke4 17.Rb4+ Kd3
18.Rb3+ Kc4 19.Rb6 Ra2 20.Rd6 Kc3
21.Rf6 Kd3 22.Rf8 Ng4 23.Kf1 Kd4
24.Rf4+ Kc5 25.Kg1 (259.363.693.512) 17040

40 253:40 -3.74 12.Rh8 Ke7 13.Rh7+ Kf8 14.Ra7 Nd3
15.Ra3 Rd2 16.Rb3 Kf7 17.Rb7+ Ke6
18.Rg7 Rd1+ 19.Kg2 Kf6 20.Ra7 Rd2
21.Ra6+ Kf5 22.Ra5+ Ke4 23.Ra4+ Kd5
24.Ra5+ Kd4 25.g4 (259.363.693.512) 17040
___________________________________________________

41 545:54 -3.74 12.Rf4 Rc1+ 13.Kg2 Rc4 14.Rf8 Rc2
15.Re8+ Kf6 16.Kf1 Nd3 17.Rf8+ Kg7
18.Rf3 Ne5 19.Rb3 Ng4 20.f3 Ne5
21.Re3 Kf6 22.Re4 Rc1+ 23.Kf2 Rc4
24.Re3 Rc2+ 25.Kf1 (538.191.301.312) 16431

41 545:54 -3.74 12.Re8+ Kf6 13.Kf1 Nd3 14.Kg1 Rd2
15.Rb8 Ke7 16.Rb7+ Ke6 17.Rg7 Rd1+
18.Kg2 Kf6 19.Ra7 Rd2 20.Ra6+ Kf5
21.Ra5+ Ke4 22.Ra4+ Kd5 23.Ra5+ Kd4
24.g4 hxg4 25.Ra4+ (538.191.301.312) 16431

40 545:54 -3.74 12.Rh8 Ke7 13.Rh7+ Kf8 14.Ra7 Nd3
15.Ra3 Rd2 16.Rb3 Kf7 17.Rb7+ Ke6
18.Rg7 Rd1+ 19.Kg2 Kf6 20.Ra7 Rd2
21.Ra6+ Kf5 22.Ra5+ Ke4 23.Ra4+ Kd5
24.Ra5+ Kd4 25.g4 (538.191.301.312) 16431
___________________________________________________

41 574:36 -3.74 12.Rf4 Rc1+ 13.Kg2 Rc4 14.Rf8 Rc2
15.Re8+ Kf6 16.Kf1 Nd3 17.Rf8+ Kg7
18.Rf3 Ne5 19.Rb3 Ng4 20.f3 Ne5
21.Re3 Kf6 22.Re4 Rc1+ 23.Kf2 Rc4
24.Re3 Rc2+ 25.Kf1 (553.727.256.706) 16061

41 574:36 -3.74 12.Re8+ Kf6 13.Kf1 Nd3 14.Kg1 Rd2
15.Rb8 Ke7 16.Rb7+ Ke6 17.Rg7 Rd1+
18.Kg2 Kf6 19.Ra7 Rd2 20.Ra6+ Kf5
21.Ra5+ Ke4 22.Ra4+ Kd5 23.Ra5+ Kd4
24.g4 hxg4 25.Ra4+ (553.727.256.706) 16061

41 574:36 -3.74 12.Rh8 Nd3 13.Rf8 Rd2 14.Kf1 Ra2
15.Kg1 Ra1+ 16.Kg2 Ke7 17.Rg8 Kf7
18.Rd8 Rd1 19.Ra8 Rd2 20.Ra7+ Ke6
21.Ra6+ Kf5 22.Ra5+ Ke4 23.Ra4+ Kd5
24.Ra5+ Kd4 25.g4 (553.727.256.706) 16061
___________________________________________________

42 692:24 -3.74 12.Rf4 Ke7 13.Re4 Kf6 14.Re3 Rd2
15.Re4 Nd3 16.Re8 Kf5 17.Rf8+ Ke6
18.Rf3 Rd1+ 19.Kh2 Ne5 20.Ra3 Nd3
21.Kg2 Rd2 22.Kf3 Rxf2+ 23.Ke3 Rg2
24.Ra6+ Kf5 25.Kxd3 (680.216.866.307) 16373

42 692:24 -3.81 12.Re8+ Kf6 13.Rb8 Nd3 14.Rd8 Rd2
15.Re8 Kf5 16.Rf8+ Ke6 17.Kf1 Ra2
18.Kg1 Ra1+ 19.Kg2 Ke7 20.Rg8 Kf7
21.Rd8 Rd1 22.Rd7+ Kf6 23.Ra7 Rd2
24.Ra6+ Kf5 25.Ra5+ (680.216.866.307) 16373

42 692:24 -3.81 12.Rh8 Nd3 13.Rf8 Rd2 14.Kf1 Ra2
15.Kg1 Ra1+ 16.Kg2 Ke7 17.Rg8 Kf7
18.Rd8 Rd1 19.Rd7+ Kf6 20.Ra7 Rd2
21.Ra6+ Kf5 22.Ra5+ Ke4 23.Ra4+ Kd5
24.Ra5+ Kd4 25.g4 (680.216.866.307) 16373

Maar hier gaat het weer mis, here it goes wrong.

43 1602:35 -2.17 12.Rf4 Rc1+ 13.Kg2 Rc4 14.Rf8 Rc2 15.Re8+ Kf6 16.Kg1 Ra2 17.Rb8 Nd3 18.Rd8 Rd2 19.Re8 Kf5 20.Rf8+ Ke6 21.Re8+ Kd5 22.Rd8+ Ke4 23.Rf8 Ra2 24.Rf6 Ne5 25.Rf4+ (1683.122.412.029) 17504
43 1602:35 -2.66 12.Rg8 Ke7 13.Rg7+ Kf6 14.Rg8 Re2 15.Ra8 Nd3 16.Ra6+ Kf5 17.f3 Rf2 18.Ra5+ Ke6 19.Ra6+ Kf7 20.Ra7+ Kg8 21.Ra8+ Kg7 22.Ra7+ Kh6 23.Rf7 Re2 24.Ra7 Ne5 25.Ra3 (1683.122.412.029) 17504
42 1602:35 -3.81 12.Re8+ Kf6 13.Rb8 Nd3 14.Rd8 Rd2 15.Re8 Kf5 16.Rf8+ Ke6 17.Kf1 Ra2 18.Kg1 Ra1+ 19.Kg2 Ke7 20.Rg8 Kf7 21.Rd8 Rd1 22.Rd7+ Kf6 23.Ra7 Rd2 24.Ra6+ Kf5 25.Ra5+ (1683.122.412.029) 17504
It seems possible that was just because the amount of hash, 512 megabyte is extemely small compared to the analysis time, but I took the best reply, 12. Rf4 without erasing TT contents and from there everything flattens out out again.

[pgn]
[Event "?"]
[Site "?"]
[Date "2017.08.17"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "8/8/5Rp1/3kn2p/7P/6P1/1r3P2/5K2 w - -"]

1. Kg1 Rc2 2. Kf1 (2. Ra6 Ke4 3. Ra4+ Kd3 4. Ra3+ Kd2
5. Kf1 Ng4 6. Ra8 Kc3 7. Rc8+ Kd3 8. Rd8+ Ke4 9. Re8+ Kf5
10. Rf8+ Ke6 11. Kg1 Ne5 {equal to pos #1 in main line}12. Rf4 {diagram}) 2... Ng4 3. Rf8 Ke6
4. Kg1 Ne5 {pos #1 in main line} 5. Re8+ Kf6 6. Ra8 Nd3 7. Rd8 Rd2 8. Re8 Kf5
9. Rf8+ Ke6 10. Rf3 (10. Kf1 Ra2 11. Rf3 Ra1+ 12. Ke2 Ne5
13. Rf4 Ke7 14. Re4 Kf6 15. Re3 Kf5) 10... Rd1+ 11. Kh2 Ne5
12. Re3 Rd2 13. Kg1 Kd5 14. Ra3 Nd3 15. Ra8 Ke6 16. Re8+
Kf6 17. Rf8+ Kg7 18. Rf3 Rd1+ 19. Kh2 Ne5 20. Ra3 Rd2
21. Kg2 Nd3 22. Ra7+ Kf6 23. Ra6+ Kf5 24. Ra5+ Ke4 25. Ra4+
Kd5 26. Ra5+ Kd4 27. Ra4+ Kc3 28. Ra3+ Kc4 $17 *[/pgn]


[D]8/8/4k1p1/4n2p/5R1P/6P1/2r2P2/6K1 b - -

Engine: Ancalagon_049 HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

47 550:23 -2.02 12...Ke7 13.Re4 Kf6 14.Re3 Nc4
15.Re4 Nd2 16.Rf4+ Ke5 17.Kg2 Rb2
18.Kg1 Ne4 19.Kg2 Ra2 20.Rf3 Ra6
21.Rf8 Nf6 22.Rc8 Kd4 23.Rd8+ Ke4
24.Rb8 Ra2 25.Kf1 Kf5 (475.868.709.750) 14409

46 550:23 -2.02 12...Rc1+ 13.Kg2 Rc4 14.Rf8 Rc2
15.Re8+ Kf6 16.Kg1 Rd2 17.Rb8 Nd7
18.Rc8 Kf5 19.Rd8 Ne5 20.Rf8+ Ke6
21.Re8+ Kd6 22.Kg2 Rb2 23.Ra8 Ng4
24.Rf8 Ra2 25.Kf1 Ke7 (475.868.709.750) 14409

46 550:23 -2.02 12...Rc4 13.Rf8 Rc2 14.Re8+ Kf6
15.Rb8 Rd2 16.Rb6+ Kf5 17.Rb5 Ke4
18.Rb4+ Kd3 19.Rb3+ Kd4 20.Rb4+ Kc5
21.Rf4 Kd6 22.Rf6+ Ke7 23.Rb6 Ra2
24.Rb7+ Ke6 25.Rb6+ Kd5 (475.868.709.750) 14409

best move: Ke6-e7 time: 550:23.796 min n/s: 14.409.875 nodes: 475.868.709.750

With Stockfish I could get much higher depths but I wanted to take some precautions against Zugzwang. If the stronger side, Black, can get White in Zugzwang here Ancalagon will detect it, the other way round Black forced into Zugzwang I thought not so likely. With Stockfish latest dev and a few changes I could easily get depth 60 even in CLI mode with default hash (I think 512 kb, or a little more, I forgot). But it would not detect Zugzwang unless by verification search.

So now I can repeat the above experiment with default Stockfish, or a modified Stockfish or with back solving, but not yet a real success.

tested with the latest asmfish (05.08.2017), no TB's :

on my pc asmfish didnt refused to take on f3 with 40/2h time-control Sad

[d]8/4k3/R4pp1/6np/7P/p4NP1/5PK1/r7 b - - 0 58

:: :: :: ::
:: :: BK ::
WR :: :: BP BP ::
:: :: :: BN BP
:: :: :: WP
BP :: :: WN WP
:: :: WP WK ::
BR :: :: ::




if 1...nxf3 its a dead draw, no surprise of course Wink
for example:

1...nxf3 2. kxf3 a2, 3. kf4 kd7, 4.ra3 kc6, 5. rc3 kb5, 6. rc2 kb4, 7. re2 kc3, 8.ke4 f5, 9.kf4 kd3, 10.rb2 and draw

1...nxf3 2. kxf3 ra2, 3.ke3 is also completely draw of course Wink


now to the thing thats called "playing chess and try to play for a win" Smile

after realizing that the rook-endgame is a totally dead draw, there is only one way to go for a win...keeping the knight on the board, at least for now !

i think 1...ne6 gives good winning chances and its due to SF's completely wrong evaluation that it is not switching to this move immediately or at least quickly Sad...thats the sad thing i wanted to talk about...not wether the position has occured in the anand-carlsen game or not !...of course i apologize for posting the wrong position !
For curiosity this is my modified Stockfish, latest dev, in this position that has a lower eval of passed pawns if there are no knights anymore. It will play Ng5-e6 for a while with really low scores, then will go to exchanging the knights, finally the score of Ng5-f3 will fall to as low as 172 centipawns for the exchange, and it will think long about for instance Ng5-e6 but in the end does not do it. Still a limited succes considering this was all in CLI mode, and just one core that Stockfish had to share with all other Windows processes Other three cores and 4 hyperthreads were for Ancalagon in the above experiment:)

info depth 59 seldepth 81 multipv 1 score cp 172 nodes 5735806400 nps 1296949 hashfull 999 tbhits 0 time 4422537 pv g5f3 g2f3 a3a2 f3e2 e7d7 e2f3 d7c7 f3e2 c7b7 a6a3 b7b6 e2f3 b6b5 f3f4 b5b4 a3a8 b4b3 a8b8 b3c3 b8a8 c3d3 a8a6 d3d2 a6a8 d2e2 f2f3 e2d2 a8a3 d2c2 a3a8 c2d1 a8a6 d1c1 a6c6 c1b2 c6b6 b2a3 b6a6 a3b4 a6a8 b4b3 a8b8 b3a4 b8a8 a4b4 a8b8 b4c5 b8c8 c5d5 c8a8 d5d6 a8a3 d6c6 a3a8 c6b6 a8a3 b6c5 a3a8 c5d5 a8a6 d5c4 a6a8 g6g5 f4f5 c4b3 a8b8 b3c2 b8c8 c2d3 c8a8 g5g4 a8a3 d3c4 f3g4 a1f1 f5g6
info depth 60 currmove g5f3 currmovenumber 1
info depth 60 currmove f6f5 currmovenumber 2
info depth 60 currmove a1g1 currmovenumber 3
info depth 60 currmove g5e4 currmovenumber 4
info depth 60 currmove a3a2 currmovenumber 5
info depth 60 currmove a1d1 currmovenumber 6
info depth 60 currmove a1e1 currmovenumber 7
info depth 60 currmove a1f1 currmovenumber 8
info depth 60 currmove e7d7 currmovenumber 9
info depth 60 currmove a1h1 currmovenumber 10
info depth 60 currmove a1b1 currmovenumber 11
info depth 60 currmove a1c1 currmovenumber 12
info depth 60 currmove g5e6 currmovenumber 13
info depth 60 currmove g5f7 currmovenumber 14
info depth 60 currmove g5h7 currmovenumber 15
info depth 60 currmove e7e8 currmovenumber 16
info depth 60 currmove g5h3 currmovenumber 17
info depth 60 currmove a1a2 currmovenumber 18
info depth 60 currmove e7f8 currmovenumber 19
info depth 60 currmove e7d8 currmovenumber 20
info depth 60 currmove e7f7 currmovenumber 21
info depth 60 seldepth 87 multipv 1 score cp 172 nodes 5778780350 nps 1295824 hashfull 999 tbhits 0 time 4459541 pv g5f3 g2f3 a3a2 f3e2 e7d7 e2f3 d7c7 f3e2 c7b7 a6a3 b7b6 e2f3 b6b5 f3f4 b5b4 a3a8 b4b3 a8b8 b3c3 b8a8 c3d3 a8a6 d3d2 a6a8 d2e2 f2f3 e2d2 a8a3 d2c2 a3a8 c2d1 a8a6 d1c1 a6c6 c1b2 c6b6 b2a3 b6a6 a3b4 a6a8 b4b3 a8b8 b3a4 b8a8 a4b4 a8a6 b4c5 a6a8 c5d5 a8a6 d5c4 a6a3 c4d4 a3a5 d4d3 a5a3 d3d2 a3a6 d2d1 a6a8 d1c1 a8a6 g6g5 f4f5 c1b2 a6b6 b2c2 b6c6 c2b3 c6b6 b3c4 b6a6 g5g4 f3f4 c4b3 a6b6 b3a4 b6a6 a4b4 f5f6 b4b3
bestmove g5f3 ponder g2f3


after i had found out that this wins like this i menaged to improve blacks play by not letting the rook to the a file where he wanna give me these annoing checks :-)...such as this:

1. ... Rb2+ 2. Kf1 Kd4 !(instead of kd5)3. Rd6+ Ke4 4. Rf6 Ng4...
the mainline for this i also gave before ;-)

for those who dont wanna search the mainline here it is again ( 2 variations) :

[d]8/8/5Rp1/2k1n2p/7P/1r4P1/4KP2/8 w - - 0 1

1. Kf1 Rb2 2. Kg1 Kd4 3. Rf4+ Kd3 4. Kf1 Ng4 5. Rf3+ Ke4 6. Rf4+ Ke5 7. Kg1 Rd2 8. Rf8 Ke6 9. Re8+ Kf7 10. Re4 Kg7 11. Re7+ Kf6 12. Re4 Ne5 13. Rf4+ Kg7 14. Re4 Nd3 15. Re7+ Kf6 16. Re8 Kf5 17. Rf8+ Ke6 18. Rf3 Rd1+ 19. Kh2 Ne5 20. Re3 Rd2 21. Kg1 Kd5 22. Ra3 Nd3 23. Ra8 Ke6 24. Re8+ Kf6 25. Rf8+ Kg7 26. Rf3 Rd1+ 27. Kh2 Ne5 28. Ra3 Rd2 29. Kg2 Nd3 30. Ra7+ Kf6 31. Ra6+ Kf5 32. Ra5+ Ke4 33. Ra4+ Kd5 34. Ra5+ Kd4 35. Ra4+ Kc3 36. Ra3+ Kc4 -+


1. Kf1 Rb2 2. Rf4 Ng4 3. Kg1 Kd6 4. Kf1 Ke6 5. Kg1 Ne5 6. Re4 Kf6 7. Re3
Rd2 8. Re4 Nd3 9. Re8 Kf5 10. Rf8+ Ke6 11. Rf3 Rd1+ 12. Kh2 Ne5 13. Re3 Rd2 14. Kg1 Kf6 15. Re4 Nd3 16. Re8 Kf5 17. Rf8+ Ke6 18. Rf3 Rd1+ 19. Kh2 Ne5 20. Re3 Rd2 21. Kg1 Kd5 22. Ra3 Nd3 23. Ra8 Ke6 24. Re8+ Kf6 25. Rf8+ Kg7 26. Rf3 Rd1+ 27. Kh2 Ne5 28. Ra3 Rd2 29. Kg2 Nd3 30. Ra7+ Kf6 31. Ra6+ Kf5 32. Ra5+ Ke4 33. Ra4+ Kd5 34. Ra5+ Kd4 35. Ra4+ Kc3 36. Ra3+ Kc4 -+

as white connot play 1. ra6?? because its loosing immediately it doesnt matter that the position is the wrong one because white cant do anything with the extra move ;-)
:)
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
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