mmt Vs. Ovyron (G4 D5 BG2)

[jp]

It certainly looks like SFdev at that TC was playing fairly randomly

That's unassisted engines for you!

Of course, as a centaur, you would do a lot better. You'd enable tablebases and "win".

More importantly, as a centaur without tablebases, you would do no better than the unassisted engine.

Based on what we've seen so far, as TB I think we could give the TBless centaur 200 moves and he still would not win. And note that all White has to do to keep going is avoid losing or exchanging a Bishop immediately, which even a computerless human can do. You certainly are not forced to find a single winning move at any time (without 50-move worries).

[Ovyron]

More importantly, as a centaur without tablebases, you would do no better than the unassisted engine.

Really? As a centaur I can go to lichess, paste a fen, and get the TB data of any position. The cursed win that Uri posted? Can play all the winning moves, no problem. Any other position that would require tablebases? I just go there and check what are the TB moves. On the fly, without downloading or storing anything.

This just proves you have no idea what being a centaur is all about, at some point we don't even need to use an engine!

[jp]

More importantly, as a centaur without tablebases, you would do no better than the unassisted engine.

Really? As a centaur I can go to lichess, paste a fen, and get the TB data of any position.

Yes, really. (e.g. it's not a TB position. Or it is a TB position but TBs are banned, just like computers are banned in OTB competitions.)

[Ovyron]

Or it is a TB position but TBs are banned

And why would you ban them?

Just ban engines altogether then, then unassisted engines can't even make their first move

[jp]

This is getting on a huge sidetrack, which I don't want, but why not? Some people might like to play endgames and not just look them up.

And of course it's reasonable to ban engines in tournaments for people who want that. The only reason people think CC is "dead" is because of engines.

White in that position, with or without humans, with or without computers, but without tablebases, will surely fail to win. But let's see if SFdev has gotten anywhere since last we saw it.

why would someone pick the one that needs precise moves from the winning side is beyond me.

This has been answered many times. It's because there may only be one winning way. You cannot just pick when and where your opponent will make a mistake, shifting the presumed opening theoretical draw to possibly a win that needs precise moves.

And it's not clear that "needs precise moves" is a good description of this example. White doesn't exactly need to be precise if I say as TB I'll give him 200 moves.

[Alayan]

More importantly, as a centaur without tablebases, you would do no better than the unassisted engine.

Really? As a centaur I can go to lichess, paste a fen, and get the TB data of any position. The cursed win that Uri posted? Can play all the winning moves, no problem. Any other position that would require tablebases? I just go there and check what are the TB moves. On the fly, without downloading or storing anything.

You're completely missing his point. Maybe you want to miss it.

He gave a tablebase position as an example precisely because we know the theoretical value of the position. Looking at unassisted engine performance and at assisted engine performance (your technique to build the tree of nodes to search and your "tagging", but no TB), we can compare then to known perfect play and see if they throw the win by failing to take the knight within 50 moves. "But I can check the TB" is completely irrelevant.

Then, we can extrapolate that if there are 5/6/7-men positions where a human-assisted engine would still fail to deliver a correct sequence of winning moves, there are even more 8-men+ positions where the same is true.

And "I would find an easier win" doesn't work in positions where there is no win easy enough for your method.

The best centaur in the world with the best hardware would still fail to spot many winning positions as such, much less convert them.

[Ovyron]

"But I can check the TB" is completely irrelevant.

It's not, because... I can check the TB.

A position needs to be posted where TBs can't be checked at all, because it's now "your side" who assumes there's a middle game position where my methods wouldn't suffice (so I fail to find the win), where presumably faster hardware would suffice, but examples where I can check the TB don't extrapolate because being able to check TBs is part of "magic tagging" (you see promising lines and you avoid those that reach endgames).

The point of the method is being able to take a shortcut to what unassisted engine would show at high depth, and perform better than it for the cases where it likes a plan that doesn't work because of misevaluation while one can have more accurate evaluation by being able to check TBs online.

In other news, I've been unable to backsolve a mate in 32 to move 40 or before in Zenmastur's challenge, because the number of lines is just absurd, so I'm going to give up now.

(still waiting for mmt's move, in case he missed my last move)

[mmt]

From the human perspective: Is white about to be up on material?!

Indeed.

1. g4 d5 2. Bg2 Bxg4 3. c4 c6 4. Qb3 e6 5. Qxb7 Nd7 6. Nc3 Ne7 7. cxd5 exd5 8. d4 Rb8 9. Qa6 Rb6 10. Qd3 Ng6 11. h3 Be6 12. Nf3 Bd6 13. h4 h5 14. b3 Nf6 15. Bg5 O-O 16. e3 Re8 17. Kf1 Bg4 18. Ne1 Bb4 19. Na4 Rb8 20. Nc2 Be7 21. f3 Be6 22. Nc5 Bc8 23. Kf2 Nd7 24. Ne6 Qa5 25. Bxe7 Rxe7 26. b4 Qb6 27. Ng5 Ba6 28. Qa3 Rbe8 29. Bf1 Bxf1 30. Raxf1 Qc7 31. Qd3 a5 32. a3 axb4 33. axb4 Qd6 34. Rfg1 Nb6 35. Qf5 Nf8 36. Re1 Nc4 37. Nh3 Ra7 38. Qxh5

[d]4rnk1/r4pp1/2pq4/3p3Q/1PnP3P/4PP1N/2N2K2/4R2R b - - 0 1
SF's evaluation is now -5.42! LC0 at -2.78.

If Ra2 then Re2.

[Ovyron]

SF's evaluation is now -5.42!

I'm impressed at the speed the eval is falling!

1. g4 d5 2. Bg2 Bxg4 3. c4 c6 4. Qb3 e6 5. Qxb7 Nd7 6. Nc3 Ne7 7. cxd5 exd5 8. d4 Rb8 9. Qa6 Rb6 10. Qd3 Ng6 11. h3 Be6 12. Nf3 Bd6 13. h4 h5 14. b3 Nf6 15. Bg5 O-O 16. e3 Re8 17. Kf1 Bg4 18. Ne1 Bb4 19. Na4 Rb8 20. Nc2 Be7 21. f3 Be6 22. Nc5 Bc8 23. Kf2 Nd7 24. Ne6 Qa5 25. Bxe7 Rxe7 26. b4 Qb6 27. Ng5 Ba6 28. Qa3 Rbe8 29. Bf1 Bxf1 30. Raxf1 Qc7 31. Qd3 a5 32. a3 axb4 33. axb4 Qd6 34. Rfg1 Nb6 35. Qf5 Nf8 36. Re1 Nc4 37. Nh3 Ra7 38. Qxh5 Ra2 39. Re2 Qe7

[d]4rnk1/4qpp1/2p5/3p3Q/1PnP3P/4PP1N/r1N1RK2/7R w - -

[zullil]

I doubt that Stockfish would fail to win from this position in a game. Here's one quick test of default Stockfish-dev self-playing. Haven't looked to see where suboptimal moves occurred.

Thanks, but maybe that's just clueless play as both attacker and defender and it's attacking self just then stumbles into mate.

Can you see whether SFdev makes any headway just analysing from the start position?

Already in progress (for too many hours).

Finally something has happened that brings a glimmer of hope ...

info depth 87 seldepth 101 multipv 1 score cp 348 nodes 241019304319 nps 68485537 hashfull 131 tbhits 0 time 3519273 pv f8e7 b6c7 a4e8 b7a5 e7c5 a5b7 c5b4 c7d8 e8b5 d8c7 b5c4 c7b6 b4f8 b6c7 f8h6 b7a5 h6f4 c7b7 c4d3 b7b6 f4e3 b6c7 d3a6 a5b7 e3f4 c7b6 a6e2 b7a5 f4e3 b6c7 d5c5 a5b7 c5b4 b7d8 b4b5 d8e6 e2d3 c7d6 d3c4 e6c7 b5a4 c7d5 e3f2 d6c6 c4b5 c6d6 a4b3 d5f4 f2b6 f4d5 b6d4 d5c7 b5c4 d6c6 d4c3 c6c5 c3f6 c7b5 c4d3 c5c6 d3e4 c6d6 b3b4 b5c7 f6d4 c7d5 b4b5 d5c7 b5b6 c7d5 b6a7 d5c7 a7b8 c7e6 d4b2 d6c5 b8b7 c5c4 e4h7 e6d4 b7b6 d4e2 b2g7 c4d5 b6a7 d5e6 g7b2 e6d7 h7d3 e2f4 d3a6 d7d6 a7b8 f4g6 b2a3 d6d5 a6b7 d5c4
info depth 88 currmove f8e7 currmovenumber 1
info depth 88 seldepth 110 multipv 1 score cp 359 lowerbound nodes 1863627803823 nps 52943145 hashfull 208 tbhits 0 time 35200549 pv f8e7
info depth 87 currmove f8e7 currmovenumber 1

[d]5B2/1n6/1k6/3K4/B7/8/8/8 w - - 0 1

I've terminated the search after 6332175484277 nodes and 36 hours. Stockfish-dev has failed to demonstrate a solution. The interested reader is welcome to analyze Stockfish's final PV for correctness ...

info depth 90 seldepth 102 multipv 1 score cp 359 nodes 4955083557701 nps 50083826 hashfull 281 tbhits 0 time 98935803 pv f8e7 b6c7 a4e8 c7b6 e7f6 b6c7 f6e5 c7b6 e8a4 b7d8 e5c3 d8b7 c3d4 b6c7 a4b5 b7d8 b5e8 d8b7 d5e6 b7d8 e6f6 c7d6 d4e5 d6d5 e5c7 d8b7 f6g6 b7c5 c7b6 c5b7 e8f7 d5d6 b6d4 b7c5 g6h7 c5e6 d4f6 e6f8 h7h6 f8d7 f6h8 d6c6 f7e6 d7c5 e6c4 c5e4 h8e5 e4d2 c4e6 c6c5 e6f5 c5b4 e5f6 b4c5 f5g6 c5b4 g6d3 b4b3 d3f5 d2f3 f6h8 f3d2 h8d4 d2f3 f5e6 b3c2 d4h8 f3e1 h6h7 e1g2 e6d7 g2e3 d7a4 c2d2 a4c6 d2e2 h7h6 e3c2 c6b5 e2d1 b5c4 c2e3 c4e6 d1d2 e6g8 e3f5 h6g5 f5e7 g8a2 d2c2 a2e6 c2d2 h8f6 e7c6 e6d7 c6b4 f6h8 b4a6
info depth 91 currmove f8e7 currmovenumber 1
stop
info depth 91 seldepth 102 multipv 1 score cp 359 nodes 6332175484277 nps 47617940 hashfull 300 tbhits 0 time 132978776 pv f8e7 b6c7 a4e8 c7b6 e7f6 b6c7 f6e5 c7b6 e8a4 b7d8 e5c3 d8b7 c3d4 b6c7 a4b5 b7d8 b5e8 d8b7 d5e6 b7d8 e6f6 c7d6 d4e5 d6d5 e5c7 d8b7 f6g6 b7c5 c7b6 c5b7 e8f7 d5d6 b6d4 b7c5 g6h7 c5e6 d4f6 e6f8 h7h6 f8d7 f6h8 d6c6 f7e6 d7c5 e6c4 c5e4 h8e5 e4d2 c4e6 c6c5 e6f5 c5b4 e5f6 b4c5 f5g6 c5b4 g6d3 b4b3 d3f5 d2f3 f6h8 f3d2 h8d4 d2f3 f5e6 b3c2 d4h8 f3e1 h6h7 e1g2 e6d7 g2e3 d7a4 c2d2 a4c6 d2e2 h7h6 e3c2 c6b5 e2d1 b5c4 c2e3 c4e6 d1d2 e6g8 e3f5 h6g5 f5e7 g8a2 d2c2 a2e6 c2d2 h8f6 e7c6 e6d7 c6b4 f6h8 b4a6
info depth 90 seldepth 111 multipv 1 score cp 369 nodes 6332175484277 nps 47617940 hashfull 300 tbhits 0 time 132978776 pv f8b4
bestmove f8b4 ponder b7d8