Winning after Qf6+!

[jhellis3]

Also, what is the supposed "winning" line for White after Bd2?

[zullil]

Also, what is the supposed "winning" line for White after Bd2?

Please see the link in the post that starts this thread.

[jhellis3]

I did? N/m I found it...

[Paloma]

I did? N/m I found it...

2nd link in the first post:
info depth 69 seldepth 183 multipv 1 score cp 392 nodes 1310302373631 nps 37939606 hashfull 1000 tbhits 0 time 34536530 pv f4f6 e7f6 g5f6 g7g8 e1d2 b6a5 d2h6 a5c3 b2c3 b3b2 h6f8 b8f8 d1b1 f8b8 f3g5 c2a3 h3h7 c6e8 h7g7 g8h8 b1b2 b8b2 g7h7 h8g8 e2g4 a3c2 g4e6 f7e6 h7g7 g8h8 g7a7 b2b8 g5e6 c2e1 h2h3 e1f3 h1g2 f3h4 g2f2 h8g8 e6g5 b8b2 f2g3 h4f5

[zullil]

An evaluation of 0.00 in the line you've posted is wrong. 3...h5 is a blunder that allows White to win. 3...Nxa3 is correct.

How sure of this line are you? Not immediately clear to me why Black sacs its queen on move 28?

I did a quick multi-pv search with Crystal after shuffling the f rook instead, and it doesn't seem find anything better than 0.00 for white?

Are we discussing this position?

[d]5rk1/1r3p2/1qb1pPp1/3pP1NB/p1pP4/PpPn2BR/1P5P/5R1K b - - 6 7

Stockfish-dev says:

+6.57 7... Bb5 8. Be2 Qxd4 9. cxd4 c3 10. bxc3 Nf4 11. Bxf4 Bxe2 12. Rb1 Bh5 13. c4 Rd8 14. c5 Kf8 15. Bd2 Ke8 16. Kg2 Rdb8 17. Kf2 Rc8 18. Bb4 Rc6 19. Rg3 Rc8 20. Rg2 Ra7 21. Rbg1 Raa8 22. Rc1 Rc7 23. Ke3 Rb8 24. Rg3 Ra8 25. Rcg1 Rcc8 26. Rb1 Ra7 27. Rc1 Ra6 28. Kf2 Rc7 29. Rb1 Kd8 30. Nh3 Kd7 31. Nf4 Ra8 32. Nxh5 gxh5 33. Rg7 Kc6 34. Ke3 Kb5 35. Kd3 Rh8 36. Rbg1 h4 37. Rg8 Rc8 (depth 46, 0:02:15)

[Spliffjiffer]

interesting position, right?
i had a deep look over 2 weeks on these positions after LT's queen sac with the help of various engines (and it was a hard but fruitful analysis)...according to this analysis i can confirm all assumptions made by Luis and Peter (except i didnt fall into Nxd4 )...
the only question that is really remaining is wether Bd2 (instead of LT's Ng5) is winning or not but this should be a nearly impossible task fmpov (at least for me with my hardware and skills)...only thing i can add is that 3....Nxa3!! is the only move that draws after Ng5

[jhellis3]

Yeah, did some more manual analysis and it looks lost regardless at that point.... it might be possible for Black to still play Nxa3 after the bishop captures h5 with the same Nb5 plan, but it makes no (apparent) sense to play this way unless allowing the pawn capture with the rook creates some issues I am not currently seeing.

[MikeB]

Qf6+ is best move , but it's just a draw after doing an overnight search with about 1.4 trillion nodes searched. Maybe if somebody searched 100 trillion nodes, they might find something different. That would require dually epyc processors for about a week.

Some quick 5 min analysis

dep score nodes time (not shown: tbhits knps seldep)
33 +50.04 6.25G 4:49.80 Qf6+ Bxf6 gxf6+ Kg8 Bf2 Ba8 Ng5 h5 Rg1 Nb4 cxb4 c3 Rxh5 cxb2 Rh7 b1=Q Rxb1 Qc6 Rg7+ Kh8 Rh7+
33 +36.40 6.44G 4:58.45 Rh6 Rh8 h4 Nxa3 Nh2 Nc2 Ng4 a3 h5 Be8 Bd2 a2 Nf6 Ra8 Kg2 a1=Q Rxa1 Nxa1 Bg4 Qc6 hxg6 fxg6 Rh1 Nc2 Qh2 Bxf6 Qh6+ Kg8 gxf6 Ra7 Bg5 Rf7 Bd2 Rb7 Bg5 Qc8 Rf1 Rf7 Bd2 Bd7 Rf3 Qf8 Qh3 h6 Bxe6 Qe8 Bxd7 Qxd7 e6 Qd8 Qh4
33 +28.77 6.45G 4:59.25 Bf2 Rh8 Nd2 Qd8 Rf3 Rf8 Nb1 Bxg5 Qg4 f5 exf6+ Bxf6 Rf1 Rb7 Bh4 Rbf7 Qxe6 Bd7 Rxf6 Bxe6 Rxf7+ Bxf7 Bxd8 Rxd8 Kg1 h5 Nd2 Re8 Kf2 Be6 Rg1 Rf8+ Bf3 Kh6 h4 Bg4 Ke2 Rf4 Rh1
33 +26.95 7.72G 5:58.99 Bd2 Nxa3 Rf1 Nc2 Bd1 a3 Bxc2 bxc2 bxa3 Qb1 Ng1 Qd1 Qh4 Rh8 Rhf3 Be8 Bc1 Rb1 Qf2 Rg8 Ne2 h5 gxh6+ Kh8 Rg3 g5 Rgg1 Qd3 Rg3 Qh7 Kg1 Rg6 Rf3 Rxh6 Rg3
33 +21.08 8.26G 6:24.08 Nd2 Qd8 Bg3 Nxa3 bxa3 Bxa3 Qf6+ Qxf6 exf6+ Kg8 Nb1 Bb2 Bd6 Rfd8 Bxb8 Rxb8 Kg2 a3 Nxa3 Bxa3 Rb1 Bd6 Bd1 Bd7 Rh4 e5 Bg4 Bc6 dxe5 Bxe5 Bf3 Bxc3 Rxc4 dxc4 Bxc6 b2 Bd5 Rc8 Kf3 Be5 Ke4 c3 Kxe5 c2

Could you please have a look at the now about 100 times repeated lines after 24.Bd2 (!) instead of 24.Ng5? (or Bf2 (?) as in your output's line)

One thing at least hasn't changed since 2014, when Lyudmil came along with the position.
Nobody is willing to have a closer look at the lines but letting SF and SF branches ponder stand alone and believe in the wrong evals, no matter if now in win- percentage instead of cp.

Nowadays we have LC0 and it even finds 22.Qf6! and 24.Bd2!, yet nobody is willing to see at least the difference to 24.Ng5 (?).
To you and Louis, Mike, I'm outa here again.
Sorry, but it's getting too time- consuming, and I don't talk about hardware- time.

Well my analysis was long time ago and at the time I only considered Bf2 as possibility winning, but I agree Bd2 is now very interesting. Still tricky.

[MikeGL]

In the meantime I gave the Nd6- line of Louis' SF, leading to a fortress, some Backward with Honey X6 FD, the fortress detection code from Joseph Ellis seems to work here really fine, Honey keeps the 0.00 in hash back to the root position after 26...Nd6.
Yet the output doesn't show much because of early repetition of Rg8 Kh7 Rh7 Kg8.
Yet that's the main trap for the engines here still, to take such threefolds for granted too early.
Probably that will have been the case with the first output after Nd4 (?) too.

[d]1r3rk1/5p1p/1qb1pPp1/3pP3/p1pP4/PpP2N1R/1Pn1B2P/3RB2K w - - 1 3
OK, so we have decided that Ng5 only leads to a draw, while Bd2 appears to win.

I am confused. If I didn't miss something from this thread, After Ng5 of white, both Nxd4 and Nd6 (on Nxa3 line) of black was already posted by Peter and both ends up in a win. So IMO, both Ng4 and Bd2 wins for white.

[jp]

I am confused. If I didn't miss something from this thread, After Ng5 of white, both Nxd4 and Nd6 (on Nxa3 line) of black was already posted by Peter and both ends up in a win. So IMO, both Ng4 and Bd2 wins for white.

The current belief in this thread is that in the Ng5 line Black's Nd6 line draws.