mmt Vs. Ovyron (G4 D5 BG2)

Discussion of computer chess matches and engine tournaments.

Moderators: bob, hgm, Harvey Williamson

Forum rules
This textbox is used to restore diagrams posted with the [d] tag before the upgrade.
jp
Posts: 1345
Joined: Mon Apr 23, 2018 5:54 am

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by jp » Wed Mar 04, 2020 8:29 am

Ovyron wrote:
Tue Mar 03, 2020 10:52 pm
zullil wrote:
Tue Mar 03, 2020 2:51 pm
With all due respect, this is a really stupid response.
It's not stupid if you assume it's linked to the subject we were discussing. If as jp says it's actually not, then my answer is stupid but the discussion is off-topic and it has nothing to do with this game thread
No, that's not correct.

I did not say it was unrelated to the thread at all. I said it had nothing to do with faster hardware. Faster hardware was one subtopic in this thread that may or may not be regarded as related to the game, but clearly has been agreed to be related to the game because no one ever raised objections to it being discussed at length here. (I've already said my bit on faster hardware. Even if someone here could afford faster hardware, millions of chess-lovers in the world cannot.)

I also said the subject discussed was not specifically about the middlegame (or the endgame, or the opening). It applies just as well to all phases of the game, or at least we don't have reasons to believe it doesn't.

Faster hardware was just one of several subtopics in this thread (and not the one I think is most interesting). Another subtopic is centaurs. I don't think faster hardware affects centaur play, because I assume a centaur with faster hardware will still use roughly the same method. Why would a centaur throw out the method he likes just because he has faster hardware?

User avatar
Ovyron
Posts: 4256
Joined: Tue Jul 03, 2007 2:30 am

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron » Wed Mar 04, 2020 8:58 am

jp wrote:
Wed Mar 04, 2020 8:29 am
I don't think faster hardware affects centaur play, because I assume a centaur with faster hardware will still use roughly the same method. Why would a centaur throw out the method he likes just because he has faster hardware?
Yeah, once you start hitting self-refutation, there's no higher place to go. The gap between me and people much higher rated would be walked as I improve, but I have to do it one game at a time (by playing stronger opposition and seeing their stronger moves, if I see one I can't reproduce in any way, that means I need faster hardware. 40.Bf4 on Zenmastur's challenge is such a move, but my 40.Bd3 is enough to win so again it's "optimal" vs. "efficient" as Bd3 can be found in 20 seconds and it wins.)

I still think those positions being discussed are off-topic because mmt can no longer reach them (he doesn't have any Bishop, so you'd need to provide a similar position mmt could still reach.)

User avatar
Ovyron
Posts: 4256
Joined: Tue Jul 03, 2007 2:30 am

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron » Wed Mar 04, 2020 11:42 am

mmt wrote:
Wed Mar 04, 2020 7:10 am
If dxe4 then fxe4.
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 40. e4 dxe4 41. fxe4 Qd7



Is there enough compensation for the pawn? Let's find out!

jp
Posts: 1345
Joined: Mon Apr 23, 2018 5:54 am

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by jp » Wed Mar 04, 2020 2:34 pm

Ovyron wrote:
Wed Mar 04, 2020 11:42 am
4rnk1/3q1pp1/2p5/7Q/1PnPP2P/7N/r1N1RK2/7R w - -
Komodo 13.2, depth 27: -1.85 (Ng5).

Uri Blass
Posts: 8765
Joined: Wed Mar 08, 2006 11:37 pm
Location: Tel-Aviv Israel

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Uri Blass » Wed Mar 04, 2020 5:51 pm

jp wrote:
Wed Mar 04, 2020 6:44 am

"The PV is 49 moves long. I guess SFdev "knows" the 50-move rule and therefore "refuses" to give a line with 50 moves, because it still "believes" it's +3.59. I guess that's also why it's "only" depth 91, seldepth 102. I assume normally 6.3 trillion nodes would be far greater depth than that (for only 5 pieces), and SFdev just widened its search instead of its normal deepening, for the same reason. Can someone confirm this?"

It seems to me it is widening the search, so I don't know why that should not help it find the direct <=49-move N capture. Why would that be "random" or "improper" search?
Suppose that stockfish search 1.Ra1 Rb8 2.Rc1 Rd8 3.Re1 Rf8 that is a draw by the 50 move rule
earlier to searching 1.Re1 Rf8 that lead to the same position but win because there is no 50 move problem.

1...Rf8 get reduced so it is always lower depth than the depth after 1.Ra1 Rb8 2.Rc1 Rd8 3.Re1 Rf8 so the hash return a draw after 1.Ra1 Rf8 and stockfish can never see the win.

After enough searching time at big depth stockfish turn off pruning by hash tables but in this case the number of lines is huge so even with fast hardware stockfish is going to need many million of years to see the draw by the 50 move rules because searching something like 10^50 lines is impossible.

Note that I do not claim that it is what happens and I did not learn the code of stockfish but it can explain why programs cannot see the shortest mate when they use the 50 move rule.

If you ignore the 50 move rules things are easier because there are no misleading draw scores by the 50 move rule to hide mates
but I think that there still may be a problem of draw score by repetition that is not correct in the hash table because in another line there is no repetition so I suspect that there may be mates that stockfish never find even if you ignore the 50 move rule.

If the last case never happen in stockfish then it may be interesting to understand why.

mmt
Posts: 216
Joined: Sun Aug 25, 2019 6:33 am
Full name: .

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by mmt » Wed Mar 04, 2020 7:43 pm

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 40. e4 dxe4 41. fxe4 Qd7 42. Ng5


If f6 then Nf3.

User avatar
Ovyron
Posts: 4256
Joined: Tue Jul 03, 2007 2:30 am

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron » Wed Mar 04, 2020 10:30 pm

mmt wrote:
Wed Mar 04, 2020 7:43 pm
If f6 then Nf3.
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 40. e4 dxe4 41. fxe4 Qd7 42. Ng5 f6 43. Nf3 Nd6


Alayan
Posts: 312
Joined: Tue Nov 19, 2019 7:48 pm
Full name: Alayan Feh

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Alayan » Thu Mar 05, 2020 3:05 am

Ethereal is beyond -3.00 now at depth 28, -3.23 d36.

mmt
Posts: 216
Joined: Sun Aug 25, 2019 6:33 am
Full name: .

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by mmt » Thu Mar 05, 2020 7:17 am

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 40. e4 dxe4 41. fxe4 Qd7 42. Ng5 f6 43. Nf3 Nd6 44. Nfe1


User avatar
Ovyron
Posts: 4256
Joined: Tue Jul 03, 2007 2:30 am

Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron » Thu Mar 05, 2020 8:10 am

mmt wrote:
Thu Mar 05, 2020 7:17 am
Nfe1
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 40. e4 dxe4 41. fxe4 Qd7 42. Ng5 f6 43. Nf3 Nd6 44. Nfe1 Rxe4


Post Reply