Historic Milestone: AlphaZero

[smatovic]

Since no one of us has access to TPU it's only fair to count in terms of what is available (for example if we had Alpha0 x64 binary compile and wanted to run it at home).
1TPU ~ 30xE5-2699v3 (18 cores machine).
4TPUs ~ 2000 Haswell cores

Apples and Bananas,

Stockfish is not able to make use of these TPUs,
and AlphaZero depends probably heavily on floating point operations (maybe half precision) to query the neural network.

So the question might be, if an stripped down x86-64 version of AlphaZero, with only some hundred or thousand of nps, is still able to beat Stockfish.....dunno.



--
Srdja

[Vinvin]

The 10 games with graph eval on Lichess :
https://lichess.org/zbCOTavB
https://lichess.org/CXpk8N5X
https://lichess.org/zDJ4IyBP
https://lichess.org/tnbEgxLG
https://lichess.org/ZMuecDNu
https://lichess.org/Y6tIfcqu
https://lichess.org/KRYcCvtd
https://lichess.org/tJzewmVJ
https://lichess.org/SfaOcHXM
https://lichess.org/B6ebUyzC

[Guenther]

The 10 games with graph eval on Lichess :
https://lichess.org/zbCOTavB
https://lichess.org/CXpk8N5X
https://lichess.org/zDJ4IyBP
https://lichess.org/tnbEgxLG
https://lichess.org/ZMuecDNu
https://lichess.org/Y6tIfcqu
https://lichess.org/KRYcCvtd
https://lichess.org/tJzewmVJ
https://lichess.org/SfaOcHXM
https://lichess.org/B6ebUyzC

What is the usual time or depth lichess-SF8 uses for those annotations?

At a first quick glance it seems impossible that SF on good hardware
is even able to make some of the bad moves that are 'colported' from blank pgn.
From the annotations it looks more likely that in reality SF8 was AlphaChess and vice versa ;-)

[Guenther]

[pgn][Event "AlphaZero-SF"]
[Site "https://lichess.org/zbCOTavB"]
[Date "2017.12.06"]
[Round "-"]
[White "AlphaZero"]
[Black "Stockfish8"]
[Result "1-0"]
[UTCDate "2017.12.06"]
[UTCTime "09:29:15"]
[WhiteElo "?"]
[BlackElo "?"]
[Variant "Standard"]
[TimeControl "-"]
[ECO "E17"]
[Opening "Queen's Indian Defense: Classical Variation, Polugaevsky Gambit"]
[Termination "Normal"]
[Annotator "lichess.org"]

1. Nf3 Nf6 2. d4 e6 3. c4 b6 4. g3 Bb7 5. Bg2 Be7 6. O-O O-O 7. d5 exd5 8. Nh4 { E17 Queen's Indian Defense: Classical Variation, Polugaevsky Gambit } c6 9. cxd5 Nxd5 10. Nf5 Nc7 11. e4 d5 12. exd5 Nxd5 13. Nc3 Nxc3 14. Qg4 g6 15. Nh6+ Kg7 16. bxc3 Bc8 17. Qf4 Qd6 18. Qa4 g5 19. Re1 Kxh6 20. h4 f6 21. Be3?! { (-0.64 → -1.48) Inaccuracy. Best move was Rxe7. } (21. Rxe7 Qxe7 22. Ba3 c5 23. Bxa8 Bf5 24. Bg2 Rd8 25. hxg5+ fxg5 26. Bc1 Kg7 27. Be3 h6) 21... Bf5? { (-1.48 → -0.25) Mistake. Best move was Kg7. } (21... Kg7 22. Rad1 Qe6 23. Bxg5 Qf7 24. Be3 b5 25. Qe4 a5 26. a4 bxa4 27. Qxa4 Re8 28. Bf1) 22. Rad1 Qa3?! { (-0.61 → 0.00) Inaccuracy. Best move was Qc7. } (22... Qc7 23. Be4) 23. Qc4 b5 24. hxg5+ fxg5 25. Qh4+ Kg6 26. Qh1 Kg7 27. Be4 Bg6 28. Bxg6 hxg6 29. Qh3 Bf6 30. Kg2 Qxa2 31. Rh1 Qg8 32. c4 Re8 33. Bd4? { (0.00 → -1.07) Mistake. Best move was Rd6. } (33. Rd6 bxc4 34. Qh6+ Kf7 35. Rxf6+ Kxf6 36. Qxg5+ Ke6 37. Rd1 Qf7 38. Qg4+ Qf5 39. Qxc4+ Ke7) 33... Bxd4? { (-1.07 → 0.00) Mistake. Best move was Rd8. } (33... Rd8 34. Bxf6+ Kxf6 35. cxb5 Rd5 36. Qg4 Nd7 37. Qf3+ Kg7 38. bxc6 Nf6 39. Rb1 Rf8 40. Rb7+) 34. Rxd4 Rd8? { (-0.24 → 1.59) Mistake. Best move was Re5. } (34... Re5 35. cxb5 cxb5 36. Rd3 Re6 37. Qh6+ Kf7 38. Qxg5 Nc6 39. Rf3+ Ke8 40. Qxb5 Rb8 41. Qc5) 35. Rxd8 Qxd8 36. Qe6 Nd7 37. Rd1 Nc5 38. Rxd8 Nxe6 39. Rxa8 Kf6 40. cxb5 cxb5 41. Kf3 Nd4+?! { (1.29 → 2.10) Inaccuracy. Best move was Ke5. } (41... Ke5 42. Ke3 Ng7 43. Rxa7 Nf5+ 44. Kd3 Kd5 45. Rb7 Nd6 46. Rb8 g4 47. Rg8 Nc4 48. Kc3) 42. Ke4 Nc6 43. Rc8 Ne7? { (1.60 → 3.92) Mistake. Best move was Nb4. } (43... Nb4 44. Rc5) 44. Rb8 Nf5?! { (3.50 → 4.33) Inaccuracy. Best move was b4. } (44... b4 45. Rxb4) 45. g4 Nh6? { (3.92 → 4.98) Mistake. Best move was Nd6+. } (45... Nd6+ 46. Kd5 Nf7 47. Rxb5 Ne5 48. Rb4 Nf3 49. Ra4 Nh2 50. Ra6+ Kg7 51. Rxa7+ Kf6 52. Ra4) 46. f3 Nf7 47. Ra8 Nd6+ 48. Kd5 Nc4 49. Rxa7 Ne3+ 50. Ke4 Nc4 51. Ra6+ Kg7 52. Rc6 Kf7?! { (4.23 → 4.78) Inaccuracy. Best move was Nd2+. } (52... Nd2+ 53. Ke3 Nb1 54. Kd3 b4 55. Rb6 Nc3 56. Rxb4 Nd5 57. Rb5 Nf4+ 58. Ke3 Nh3 59. Ke4) 53. Rc5 Ke6?! { (4.01 → 4.87) Inaccuracy. Best move was Kf6. } (53... Kf6 54. Rd5) 54. Rxg5 Kf6 55. Rc5 g5 56. Kd4 { Black resigns. } 1-0
[/pgn]

I tried with the 'old' SF8 here and even with 1 cpu setting it would never play 21. Be3??
Also it would always go for a dead draw by repetition with 16. Nf5+ (=) instead of the weaker 16. bxc3?

This raises some questions. Did they perhaps add extreme contempt to SF? Of course the whole setup could be erroneous anyways.

Thanks to Vincent for the lichess analysis pgn.

[Vinvin]

The 10 games with graph eval on Lichess :
https://lichess.org/zbCOTavB
https://lichess.org/CXpk8N5X
https://lichess.org/zDJ4IyBP
https://lichess.org/tnbEgxLG
https://lichess.org/ZMuecDNu
https://lichess.org/Y6tIfcqu
https://lichess.org/KRYcCvtd
https://lichess.org/tJzewmVJ
https://lichess.org/SfaOcHXM
https://lichess.org/B6ebUyzC

What is the usual time or depth lichess-SF8 uses for those annotations?

At a first quick glance it seems impossible that SF on good hardware
is even able to make some of the bad moves that are 'colported' from blank pgn.
From the annotations it looks more likely that in reality SF8 was AlphaChess and vice versa

I don't remember exactly but from my memory the analyse uses around 3 sec per move on a 2 GHz CPU.
The moves in the game has been played with Stockfish 8 on 64 CPUs 1 min/per move (quote from the paper : "In this section we include 10 example games played by AlphaZero against Stockfish during the 100 game match using 1 minute per move." )
70 Mnodes/sec for SF8 vs 80Knodes/sec for AlphaZero, see tables S4 in the paper : https://arxiv.org/pdf/1712.01815.pdf

[zenpawn]

[pgn][Event "AlphaZero-SF"]
[Site "https://lichess.org/zbCOTavB"]
[Date "2017.12.06"]
[Round "-"]
[White "AlphaZero"]
[Black "Stockfish8"]
[Result "1-0"]
[UTCDate "2017.12.06"]
[UTCTime "09:29:15"]
[WhiteElo "?"]
[BlackElo "?"]
[Variant "Standard"]
[TimeControl "-"]
[ECO "E17"]
[Opening "Queen's Indian Defense: Classical Variation, Polugaevsky Gambit"]
[Termination "Normal"]
[Annotator "lichess.org"]

1. Nf3 Nf6 2. d4 e6 3. c4 b6 4. g3 Bb7 5. Bg2 Be7 6. O-O O-O 7. d5 exd5 8. Nh4 { E17 Queen's Indian Defense: Classical Variation, Polugaevsky Gambit } c6 9. cxd5 Nxd5 10. Nf5 Nc7 11. e4 d5 12. exd5 Nxd5 13. Nc3 Nxc3 14. Qg4 g6 15. Nh6+ Kg7 16. bxc3 Bc8 17. Qf4 Qd6 18. Qa4 g5 19. Re1 Kxh6 20. h4 f6 21. Be3?! { (-0.64 → -1.48) Inaccuracy. Best move was Rxe7. } (21. Rxe7 Qxe7 22. Ba3 c5 23. Bxa8 Bf5 24. Bg2 Rd8 25. hxg5+ fxg5 26. Bc1 Kg7 27. Be3 h6) 21... Bf5? { (-1.48 → -0.25) Mistake. Best move was Kg7. } (21... Kg7 22. Rad1 Qe6 23. Bxg5 Qf7 24. Be3 b5 25. Qe4 a5 26. a4 bxa4 27. Qxa4 Re8 28. Bf1) 22. Rad1 Qa3?! { (-0.61 → 0.00) Inaccuracy. Best move was Qc7. } (22... Qc7 23. Be4) 23. Qc4 b5 24. hxg5+ fxg5 25. Qh4+ Kg6 26. Qh1 Kg7 27. Be4 Bg6 28. Bxg6 hxg6 29. Qh3 Bf6 30. Kg2 Qxa2 31. Rh1 Qg8 32. c4 Re8 33. Bd4? { (0.00 → -1.07) Mistake. Best move was Rd6. } (33. Rd6 bxc4 34. Qh6+ Kf7 35. Rxf6+ Kxf6 36. Qxg5+ Ke6 37. Rd1 Qf7 38. Qg4+ Qf5 39. Qxc4+ Ke7) 33... Bxd4? { (-1.07 → 0.00) Mistake. Best move was Rd8. } (33... Rd8 34. Bxf6+ Kxf6 35. cxb5 Rd5 36. Qg4 Nd7 37. Qf3+ Kg7 38. bxc6 Nf6 39. Rb1 Rf8 40. Rb7+) 34. Rxd4 Rd8? { (-0.24 → 1.59) Mistake. Best move was Re5. } (34... Re5 35. cxb5 cxb5 36. Rd3 Re6 37. Qh6+ Kf7 38. Qxg5 Nc6 39. Rf3+ Ke8 40. Qxb5 Rb8 41. Qc5) 35. Rxd8 Qxd8 36. Qe6 Nd7 37. Rd1 Nc5 38. Rxd8 Nxe6 39. Rxa8 Kf6 40. cxb5 cxb5 41. Kf3 Nd4+?! { (1.29 → 2.10) Inaccuracy. Best move was Ke5. } (41... Ke5 42. Ke3 Ng7 43. Rxa7 Nf5+ 44. Kd3 Kd5 45. Rb7 Nd6 46. Rb8 g4 47. Rg8 Nc4 48. Kc3) 42. Ke4 Nc6 43. Rc8 Ne7? { (1.60 → 3.92) Mistake. Best move was Nb4. } (43... Nb4 44. Rc5) 44. Rb8 Nf5?! { (3.50 → 4.33) Inaccuracy. Best move was b4. } (44... b4 45. Rxb4) 45. g4 Nh6? { (3.92 → 4.98) Mistake. Best move was Nd6+. } (45... Nd6+ 46. Kd5 Nf7 47. Rxb5 Ne5 48. Rb4 Nf3 49. Ra4 Nh2 50. Ra6+ Kg7 51. Rxa7+ Kf6 52. Ra4) 46. f3 Nf7 47. Ra8 Nd6+ 48. Kd5 Nc4 49. Rxa7 Ne3+ 50. Ke4 Nc4 51. Ra6+ Kg7 52. Rc6 Kf7?! { (4.23 → 4.78) Inaccuracy. Best move was Nd2+. } (52... Nd2+ 53. Ke3 Nb1 54. Kd3 b4 55. Rb6 Nc3 56. Rxb4 Nd5 57. Rb5 Nf4+ 58. Ke3 Nh3 59. Ke4) 53. Rc5 Ke6?! { (4.01 → 4.87) Inaccuracy. Best move was Kf6. } (53... Kf6 54. Rd5) 54. Rxg5 Kf6 55. Rc5 g5 56. Kd4 { Black resigns. } 1-0
[/pgn]

I tried with the 'old' SF8 here and even with 1 cpu setting it would never play 21. Be3??
Also it would always go for a dead draw by repetition with 16. Nf5+ (=) instead of the weaker 16. bxc3?

This raises some questions. Did they perhaps add extreme contempt to SF? Of course the whole setup could be erroneous anyways.

Thanks to Vincent for the lichess analysis pgn.

Those are AlphaZero moves you've called out as odd.

[Vinvin]

[pgn][Event "AlphaZero-SF"]
[Site "https://lichess.org/zbCOTavB"]
[Date "2017.12.06"]
[Round "-"]
[White "AlphaZero"]
[Black "Stockfish8"]
[Result "1-0"]
[UTCDate "2017.12.06"]
[UTCTime "09:29:15"]
[WhiteElo "?"]
[BlackElo "?"]
[Variant "Standard"]
[TimeControl "-"]
[ECO "E17"]
[Opening "Queen's Indian Defense: Classical Variation, Polugaevsky Gambit"]
[Termination "Normal"]
[Annotator "lichess.org"]

1. Nf3 Nf6 2. d4 e6 3. c4 b6 4. g3 Bb7 5. Bg2 Be7 6. O-O O-O 7. d5 exd5 8. Nh4 { E17 Queen's Indian Defense: Classical Variation, Polugaevsky Gambit } c6 9. cxd5 Nxd5 10. Nf5 Nc7 11. e4 d5 12. exd5 Nxd5 13. Nc3 Nxc3 14. Qg4 g6 15. Nh6+ Kg7 16. bxc3 Bc8 17. Qf4 Qd6 18. Qa4 g5 19. Re1 Kxh6 20. h4 f6 21. Be3?! { (-0.64 → -1.48) Inaccuracy. Best move was Rxe7. } (21. Rxe7 Qxe7 22. Ba3 c5 23. Bxa8 Bf5 24. Bg2 Rd8 25. hxg5+ fxg5 26. Bc1 Kg7 27. Be3 h6) 21... Bf5? { (-1.48 → -0.25) Mistake. Best move was Kg7. } (21... Kg7 22. Rad1 Qe6 23. Bxg5 Qf7 24. Be3 b5 25. Qe4 a5 26. a4 bxa4 27. Qxa4 Re8 28. Bf1) 22. Rad1 Qa3?! { (-0.61 → 0.00) Inaccuracy. Best move was Qc7. } (22... Qc7 23. Be4) 23. Qc4 b5 24. hxg5+ fxg5 25. Qh4+ Kg6 26. Qh1 Kg7 27. Be4 Bg6 28. Bxg6 hxg6 29. Qh3 Bf6 30. Kg2 Qxa2 31. Rh1 Qg8 32. c4 Re8 33. Bd4? { (0.00 → -1.07) Mistake. Best move was Rd6. } (33. Rd6 bxc4 34. Qh6+ Kf7 35. Rxf6+ Kxf6 36. Qxg5+ Ke6 37. Rd1 Qf7 38. Qg4+ Qf5 39. Qxc4+ Ke7) 33... Bxd4? { (-1.07 → 0.00) Mistake. Best move was Rd8. } (33... Rd8 34. Bxf6+ Kxf6 35. cxb5 Rd5 36. Qg4 Nd7 37. Qf3+ Kg7 38. bxc6 Nf6 39. Rb1 Rf8 40. Rb7+) 34. Rxd4 Rd8? { (-0.24 → 1.59) Mistake. Best move was Re5. } (34... Re5 35. cxb5 cxb5 36. Rd3 Re6 37. Qh6+ Kf7 38. Qxg5 Nc6 39. Rf3+ Ke8 40. Qxb5 Rb8 41. Qc5) 35. Rxd8 Qxd8 36. Qe6 Nd7 37. Rd1 Nc5 38. Rxd8 Nxe6 39. Rxa8 Kf6 40. cxb5 cxb5 41. Kf3 Nd4+?! { (1.29 → 2.10) Inaccuracy. Best move was Ke5. } (41... Ke5 42. Ke3 Ng7 43. Rxa7 Nf5+ 44. Kd3 Kd5 45. Rb7 Nd6 46. Rb8 g4 47. Rg8 Nc4 48. Kc3) 42. Ke4 Nc6 43. Rc8 Ne7? { (1.60 → 3.92) Mistake. Best move was Nb4. } (43... Nb4 44. Rc5) 44. Rb8 Nf5?! { (3.50 → 4.33) Inaccuracy. Best move was b4. } (44... b4 45. Rxb4) 45. g4 Nh6? { (3.92 → 4.98) Mistake. Best move was Nd6+. } (45... Nd6+ 46. Kd5 Nf7 47. Rxb5 Ne5 48. Rb4 Nf3 49. Ra4 Nh2 50. Ra6+ Kg7 51. Rxa7+ Kf6 52. Ra4) 46. f3 Nf7 47. Ra8 Nd6+ 48. Kd5 Nc4 49. Rxa7 Ne3+ 50. Ke4 Nc4 51. Ra6+ Kg7 52. Rc6 Kf7?! { (4.23 → 4.78) Inaccuracy. Best move was Nd2+. } (52... Nd2+ 53. Ke3 Nb1 54. Kd3 b4 55. Rb6 Nc3 56. Rxb4 Nd5 57. Rb5 Nf4+ 58. Ke3 Nh3 59. Ke4) 53. Rc5 Ke6?! { (4.01 → 4.87) Inaccuracy. Best move was Kf6. } (53... Kf6 54. Rd5) 54. Rxg5 Kf6 55. Rc5 g5 56. Kd4 { Black resigns. } 1-0
[/pgn]

I tried with the 'old' SF8 here and even with 1 cpu setting it would never play 21. Be3??
Also it would always go for a dead draw by repetition with 16. Nf5+ (=) instead of the weaker 16. bxc3?

This raises some questions. Did they perhaps add extreme contempt to SF? Of course the whole setup could be erroneous anyways.

Thanks to Vincent for the lichess analysis pgn.

White is AlphaZero in this game and white won

[melajara]

Well, this might be settled by having AlphaZero as a special guest on TCEC 11.

Meanwhile, Google has enough time to optimize then scale down a custom version compatible with TCEC hardware

[kranium]

[pgn][Event "AlphaZero-SF"]
[Site "https://lichess.org/zbCOTavB"]
[Date "2017.12.06"]
[Round "-"]
[White "AlphaZero"]
[Black "Stockfish8"]
[Result "1-0"]
[UTCDate "2017.12.06"]
[UTCTime "09:29:15"]
[WhiteElo "?"]
[BlackElo "?"]
[Variant "Standard"]
[TimeControl "-"]
[ECO "E17"]
[Opening "Queen's Indian Defense: Classical Variation, Polugaevsky Gambit"]
[Termination "Normal"]
[Annotator "lichess.org"]

1. Nf3 Nf6 2. d4 e6 3. c4 b6 4. g3 Bb7 5. Bg2 Be7 6. O-O O-O 7. d5 exd5 8. Nh4 { E17 Queen's Indian Defense: Classical Variation, Polugaevsky Gambit } c6 9. cxd5 Nxd5 10. Nf5 Nc7 11. e4 d5 12. exd5 Nxd5 13. Nc3 Nxc3 14. Qg4 g6 15. Nh6+ Kg7 16. bxc3 Bc8 17. Qf4 Qd6 18. Qa4 g5 19. Re1 Kxh6 20. h4 f6 21. Be3?! { (-0.64 → -1.48) Inaccuracy. Best move was Rxe7. } (21. Rxe7 Qxe7 22. Ba3 c5 23. Bxa8 Bf5 24. Bg2 Rd8 25. hxg5+ fxg5 26. Bc1 Kg7 27. Be3 h6) 21... Bf5? { (-1.48 → -0.25) Mistake. Best move was Kg7. } (21... Kg7 22. Rad1 Qe6 23. Bxg5 Qf7 24. Be3 b5 25. Qe4 a5 26. a4 bxa4 27. Qxa4 Re8 28. Bf1) 22. Rad1 Qa3?! { (-0.61 → 0.00) Inaccuracy. Best move was Qc7. } (22... Qc7 23. Be4) 23. Qc4 b5 24. hxg5+ fxg5 25. Qh4+ Kg6 26. Qh1 Kg7 27. Be4 Bg6 28. Bxg6 hxg6 29. Qh3 Bf6 30. Kg2 Qxa2 31. Rh1 Qg8 32. c4 Re8 33. Bd4? { (0.00 → -1.07) Mistake. Best move was Rd6. } (33. Rd6 bxc4 34. Qh6+ Kf7 35. Rxf6+ Kxf6 36. Qxg5+ Ke6 37. Rd1 Qf7 38. Qg4+ Qf5 39. Qxc4+ Ke7) 33... Bxd4? { (-1.07 → 0.00) Mistake. Best move was Rd8. } (33... Rd8 34. Bxf6+ Kxf6 35. cxb5 Rd5 36. Qg4 Nd7 37. Qf3+ Kg7 38. bxc6 Nf6 39. Rb1 Rf8 40. Rb7+) 34. Rxd4 Rd8? { (-0.24 → 1.59) Mistake. Best move was Re5. } (34... Re5 35. cxb5 cxb5 36. Rd3 Re6 37. Qh6+ Kf7 38. Qxg5 Nc6 39. Rf3+ Ke8 40. Qxb5 Rb8 41. Qc5) 35. Rxd8 Qxd8 36. Qe6 Nd7 37. Rd1 Nc5 38. Rxd8 Nxe6 39. Rxa8 Kf6 40. cxb5 cxb5 41. Kf3 Nd4+?! { (1.29 → 2.10) Inaccuracy. Best move was Ke5. } (41... Ke5 42. Ke3 Ng7 43. Rxa7 Nf5+ 44. Kd3 Kd5 45. Rb7 Nd6 46. Rb8 g4 47. Rg8 Nc4 48. Kc3) 42. Ke4 Nc6 43. Rc8 Ne7? { (1.60 → 3.92) Mistake. Best move was Nb4. } (43... Nb4 44. Rc5) 44. Rb8 Nf5?! { (3.50 → 4.33) Inaccuracy. Best move was b4. } (44... b4 45. Rxb4) 45. g4 Nh6? { (3.92 → 4.98) Mistake. Best move was Nd6+. } (45... Nd6+ 46. Kd5 Nf7 47. Rxb5 Ne5 48. Rb4 Nf3 49. Ra4 Nh2 50. Ra6+ Kg7 51. Rxa7+ Kf6 52. Ra4) 46. f3 Nf7 47. Ra8 Nd6+ 48. Kd5 Nc4 49. Rxa7 Ne3+ 50. Ke4 Nc4 51. Ra6+ Kg7 52. Rc6 Kf7?! { (4.23 → 4.78) Inaccuracy. Best move was Nd2+. } (52... Nd2+ 53. Ke3 Nb1 54. Kd3 b4 55. Rb6 Nc3 56. Rxb4 Nd5 57. Rb5 Nf4+ 58. Ke3 Nh3 59. Ke4) 53. Rc5 Ke6?! { (4.01 → 4.87) Inaccuracy. Best move was Kf6. } (53... Kf6 54. Rd5) 54. Rxg5 Kf6 55. Rc5 g5 56. Kd4 { Black resigns. } 1-0
[/pgn]

I tried with the 'old' SF8 here and even with 1 cpu setting it would never play 21. Be3??
Also it would always go for a dead draw by repetition with 16. Nf5+ (=) instead of the weaker 16. bxc3?

This raises some questions. Did they perhaps add extreme contempt to SF? Of course the whole setup could be erroneous anyways.

Thanks to Vincent for the lichess analysis pgn.

Stockfish greatly prefers Be3 on my i7 4930k w/12 threads

FEN: rnb2r2/p3b2p/1ppq1p1k/6p1/Q6P/2P3P1/P4PB1/R1B1R1K1 w - - 0 21

Stockfish 8 64 POPCNT Arena multiPV=2 after 20. h4 f6 :
---------------------------------------------------------------------------
39/78 42:31 31,322,562k 12,274k -0.54 Re1xe7 Qd6xe7 Bc1a3 c6c5 Bg2xa8 Bc8f5 Ba8f3 Qe7d7 Qa4b3 Qd7e6 Ra1d1 g5xh4 Qb3a4 h4xg3 Ba3c1+ Kh6g7 f2xg3 Qe6e7 Bc1f4 Rf8e8 Kg1h2 a7a6 Rd1d5 Bf5d7 Qa4d1 Bd7c6 Rd5d2 Bc6xf3 Qd1xf3 Qe7e6 Qf3b7+ Qe6f7 Qb7xb6 Qf7h5+ Kh2g2 Re8e2+ Rd2xe2 Qh5xe2+ Kg2h3 Nb8d7 Qb6d6 Qe2h5+ Kh3g2 Nd7e5 Qd6e7+ Qh5f7 Qe7xf7+ Kg7xf7 Bf4e3 c5c4 Kg2f2 Ne5g4+ Kf2e2 Ng4xe3 Ke2xe3

39/78 42:31 31,322,562k 12,274k 0.00 Bc1e3 Bc8f5 Ra1d1 Qd6a3 h4xg5+ f6xg5 Qa4h4+ Kh6g6 Qh4h1 Kg6g7 Be3c1 Qa3c5 Bc1e3 Qc5a3

[Guenther]

White is AlphaZero in this game :-) and white won :-)

oops my bad.

This means the excessive SF blunder here is 34...Rd8???
No time to analyse now.

Guenther