The Observer Effect

Did Ian Nepomniachtchi miss a win against Fabiano Caruana in their Round 2 matchup at the Sinquefield Cup? It depends on what you mean by “miss.” The Caruana-Nepomniachtchi game was one of six draws in yesterday’s second round, and one of eleven draws (out of twelve games) in the first two days of the event. It might be tempting to draw dovish conclusions from this small sample, but in this case, such a conclusion would be wrong.

courtesy STLCC

Excluding the perfunctory Karjakin-Mamedyarov draw in Round 1, many of the draws have been solid, fighting games. This was certainly the case yesterday, with Mamedyarov and Nakamura going so far as to play to bare kings.

Nakamura (photo Justin Kellar)

[pgn]

[Event "7th Sinquefield Cup 2019"]
[Site "Saint Louis USA"]
[Date "2019.08.18"]
[Round "2.6"]
[White "Mamedyarov, Shakhriyar"]
[Black "Nakamura, Hikaru"]
[Result "1/2-1/2"]
[ECO "D37"]
[WhiteElo "2764"]
[BlackElo "2743"]
[PlyCount "88"]
[EventDate "2019.08.17"]

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 Be7 5. Bf4 O-O 6. e3 c5 7. dxc5 Bxc5 8. Qc2
Nc6 9. a3 Qa5 10. O-O-O Be7 11. Rg1 a6 12. g4 dxc4 13. Bxc4 b5 14. g5 Nh5 15.
Bd3 b4 16. Bxh7+ Kh8 17. Be4 bxc3 18. Bxc6 cxb2+ 19. Kb1 Qxa3 20. Qxb2 Qxb2+
21. Kxb2 Ra7 22. Bd6 Bxd6 23. Rxd6 Bb7 24. Ne5 Bxc6 25. Rxc6 Rb8+ 26. Kc2 a5
27. Rb1 Rd8 28. Rbb6 Kh7 29. f4 Rda8 30. Kb3 a4+ 31. Ka3 f6 32. Nf3 Rd7 33. Rd6
Rxd6 34. Rxd6 Rc8 35. gxf6 gxf6 36. Rxe6 Nxf4 37. exf4 Rc3+ 38. Kxa4 Rxf3 39.
Rxf6 Kg7 40. Rb6 Rxf4+ 41. Rb4 Rxb4+ 42. Kxb4 Kg6 43. h3 Kh5 44. h4 Kxh4
1/2-1/2

[/pgn]

World Champion Magnus Carlsen took another step, if a shaky one, towards normalcy after a disastrous (by his standards) Saint Louis Rapid and Blitz. Playing Black, Carlsen held the draw against Vishy Anand in 45 moves.

Eschewing his standard 4…dxc6 in the Rossolimo, Carlsen fell behind in development in the late opening, prompting this interesting comment from the Champ in the Confessional booth. https://twitter.com/GrandChessTour/status/1163165721775497217 Frequent CLO contributor Eric Rosen pointed out on Twitter that this pawn structure – with pawns on f6 and d6 – is not unknown in Carlsen’s practice… if you have studied his lichess games?!?! https://twitter.com/IM_Rosen/status/1163168835509395456 Ultimately Carlsen did manage to castle, and he managed to draw Anand without too much difficulty.

[pgn]

[Event "7th Sinquefield Cup 2019"]
[Site "Saint Louis USA"]
[Date "2019.08.18"]
[Round "2.1"]
[White "Anand, Viswanathan"]
[Black "Carlsen, Magnus"]
[Result "1/2-1/2"]
[ECO "B31"]
[WhiteElo "2756"]
[BlackElo "2882"]
[PlyCount "89"]
[EventDate "2019.08.17"]

1. e4 c5 2. Nf3 Nc6 3. Bb5 g6 4. Bxc6 bxc6 5. d4 Bg7 6. dxc5 Qa5+ 7. Nbd2 Qxc5
8. O-O d6 9. Re1 f6 10. a3 Nh6 11. b4 Qh5 12. c4 O-O 13. Qa4 Bd7 14. Nf1 Nf7
15. Ng3 Qg4 16. c5 e5 17. cxd6 c5 18. Qb3 cxb4 19. axb4 Qe6 20. Qxe6 Bxe6 21.
Be3 a6 22. Rec1 Rfd8 23. Nd2 Bf8 24. Nc4 Rac8 25. Bc5 Bxc4 26. Rxc4 Nxd6 27.
Rcc1 Rc6 28. f3 Nb5 29. Bxf8 Rxc1+ 30. Rxc1 Kxf8 31. Nf1 Nd4 32. Rc4 Ke7 33.
Ne3 Kd6 34. Rc5 Nc6 35. Rd5+ Ke7 36. b5 axb5 37. Rxb5 Rb8 38. Rxb8 Nxb8 39. Kf2
Ke6 40. g3 Nd7 41. Nc4 Nc5 42. Ke3 Nd7 43. Kf2 Nc5 44. Ke3 Nd7 45. Kf2 1/2-1/2

[/pgn]

Carlsen took another trip to the Confessional, this time to praise Maxime Vachier-Lagrave for his textbook positioning of his pieces against Wesley So. https://twitter.com/GrandChessTour/status/1163172069158379520 As it turned out, So’s extra pawn (and later exchange) was sufficient compensation for MVL’s “perfect positional harmony,” and the game was drawn without great difficulty.

[pgn]

[Event "7th Sinquefield Cup 2019"]
[Site "Saint Louis USA"]
[Date "2019.08.18"]
[Round "2.5"]
[White "Vachier-Lagrave, Maxime"]
[Black "So, Wesley"]
[Result "1/2-1/2"]
[ECO "C53"]
[WhiteElo "2778"]
[BlackElo "2776"]
[PlyCount "85"]
[EventDate "2019.08.17"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Nf6 5. d3 d6 6. O-O a6 7. a4 Ba7 8. Re1
O-O 9. h3 Kh8 10. d4 Ng8 11. b4 exd4 12. cxd4 Nxb4 13. Nc3 a5 14. Bf4 f6 15.
Qb3 Ne7 16. Rad1 c6 17. Bc1 d5 18. exd5 Bf5 19. dxc6 Bc2 20. cxb7 Rb8 21. Qa3
Bxd1 22. Rxd1 Nf5 23. Nb5 Nd6 24. Bf1 Nxb5 25. axb5 Rxb7 26. Bd2 Nc2 27. Qa4
Nxd4 28. Nxd4 Qxd4 29. Qxd4 Bxd4 30. Bxa5 Bb6 31. Bxb6 Rxb6 32. g3 g6 33. Rd7
Rfb8 34. Bc4 R8b7 35. Rd8+ Kg7 36. Bd5 Rxb5 37. Bxb7 Rxb7 38. Kg2 h5 39. h4 Ra7
40. Rc8 Rb7 41. Rd8 Ra7 42. Rc8 Rb7 43. Rd8 1/2-1/2

[/pgn]

The highlight of the round, and the main focus of this report, had to be the game between Fabiano Caruana and Ian Nepomniachtchi, and in particular, the position after Black’s 27th move.

Here Caruana played 28.Qg2, with the clear idea of countering a potential Black rook sacrifice on a3 with 28…Rxa3 29.bxa3 Qxa3 30.f3, covering the second rank and snuffing out any danger. The problem, as anyone with an engine running immediately saw, is that after the Dvoretsky-esque backward move 30…Qa7! Black was nearly winning. https://twitter.com/GrandChessTour/status/1163194565442134018 In the game, and despite (per his post-game interview) his constantly being on the lookout for …Rxa3 shots, Nepomniachtchi instead chose what he thought was another winning move, 28…Bf8?!, and the game soon petered out to a draw.

[pgn]

[Event "7th Sinquefield Cup 2019"]
[Site "Saint Louis USA"]
[Date "2019.08.18"]
[Round "2.2"]
[White "Caruana, Fabiano"]
[Black "Nepomniachtchi, Ian"]
[Result "1/2-1/2"]
[ECO "B90"]
[WhiteElo "2818"]
[BlackElo "2774"]
[Annotator "Hartmann,John"]
[PlyCount "70"]
[EventDate "2019.08.17"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. h3 e5 7. Nb3 Be7 8. g4
b5 9. g5 Nfd7 10. h4 Nb6 11. Be3 Be6 12. Bxb6 Qxb6 13. Qf3 b4 14. Nd5 Bxd5 15.
exd5 Nd7 16. O-O-O a5 17. Kb1 a4 18. Nd2 Nc5 19. Bd3 b3 20. cxb3 axb3 21. a3
Ra4 22. Ne4 Nxe4 23. Bxe4 O-O 24. Rhg1 Qa7 25. h5 g6 26. Rd3 Rb8 27. hxg6 hxg6
{[#]} 28. Qg2 $2 (28. Rh1 Rxa3 $140 $6 (28... Bxg5 $1) 29. bxa3 Qxa3 30. Qe2
$16) (28. Rg4 $5 {is another idea, defending the bishop and threatening Rxb3.})
28... Bf8 $6 (28... Rxa3 $1 29. bxa3 Qxa3 30. f3 {looks to stop all the
threats, but now Black has a total 'computer-eyes' move:} (30. f4 Qa7 $1 {
is similar, except that Black also has the option of ...exf4 and ...Bf8-g7 in
certain lines} (30... Qa4 $1)) 30... Qa7 $1 {when ...b2 has too many threats
for White to stop. Play might continue} 31. Rdd1 (31. Rf1 b2 {and ...Qa1+
followed by promotion is crushing}) (31. Rh1 b2) 31... b2 32. Kc2 {and now
Black has to find} Qc5+ (32... Bd8 {also works}) 33. Kd2 (33. Kb1 Qa3 34. Kc2
Bd8 {wti ...Ba5 and the mating net gets tighter}) 33... Rb3 $19) 29. f3 Rc4 30.
Rh1 Qc7 31. Qh2 Bg7 32. Qe2 Bf8 33. Qh2 Bg7 34. Qe2 Bf8 35. Qh2 Bg7 1/2-1/2

[/pgn]

Question: did Nepo miss a win? Let’s begin by stipulating that 30…Qa7 is deeply counter-intuitive. Black sacrifices a rook for an attack, but then is supposed to switch gears and make a backwards queen move? It’s the kind of move that engines see immediately, but humans with their biases will (in my opinion) more often than not miss it. With engines running, however, the whole idea is obvious once we see the key move. And it’s for that reason that the commentators, who have benefit of hints from the engine in the diagram window (if not outright confirmation from Maurice), were right to quote a line from Anand in this situation. Paraphrasing, Anand said that the problem with the engine is that in certain positions, once you see its move, you can’t “unsee” it. On that basis we retroactively attribute blame or fault to players in situations where, from any reasonable practical perspective, they can’t possibly be expected to find the move in question without a hint or silicon assistance. https://twitter.com/GrandChessTour/status/1163198411794976768 While it’s not nothing that Wesley So was able to find the key move with a bit of a hint from Maurice Ashley, the fact that So was asked the question changes the nature of the task. Here we run into something like what quantum physicists (and students of German Idealism) think of as the observer effect. Measurement of phenomena, particularly quantum phenomena, is altered by the presence of instrumentation or observers. Somewhat analogously, our understanding of chess positiosn is altered (retroactively) by the presence of chess engines. Once the engine shows us something, we can’t ‘unsee’ it, and it causes us to lose objectivity about our thought processes. So back to the question at hand. Should Nepomniachtchi realistically have found 30…Qa7, and should we thus consider this a miss? Denes Boros answered in the negative: https://twitter.com/Gmasterg4/status/1163192855323652096 The Twitterati are less generous, if Jennifer Shahade’s poll is any indication. https://twitter.com/JenShahade/status/1163505219566821380 As for me, I’m on the fence. Certainly 30…Qa7 is very difficult to find, but it’s not as difficult as 68…Bh4! (and 70…Ng1!!) were in Game 6 of the Carlsen-Caruana match. (Thanks to Jen Shahade for the example.) There, no one could reasonably have expected Caruana to find the arcane ideas deep in the field of analysis; here, however, it doesn’t feel implausible that Nepo could have tracked it down. STANDINGS AFTER ROUND 2