Definitely. There were masters in the past that I believe were better defenders than Carlsen (such as Lasker, Capablanca, and Petrosian). (Having said that, I believe that Carlsen IS the best defender in the world, currently, together with Karjakin.) <21. Re2, as <SirRuthless> suggests, appears to be an idea that the human mind, and especially a Super GMs mind, can easily understand.> Capablanca probably would have moved 21. Re2 in a jiffy. It looks like a perfectly logical move to mobilize the rook. From 1909 to 1924 Capa made something like less than a single definitively losing error per year, and in several cases defended more difficult positions than this, including the game above where Marshall introduced his brilliant idea for the first time. I believe it was his ability to see and avoid tactical errors better than anyone in chess history which made him nearly invincible. (You have to make a losing error in order to lose, and the young Capablanca did not make many of those.)

Going back to Bu's dauntlessly courageous strategy for this game, I believe this again is another proof that it's the only way to play against Carlsen and still hope to win. Bu offers a gambit pawn, Carlsen as usual grabs it (he always does). Bu sacs a Bishop. Carlsen tries to retain the piece with 17. Nf1 when he could have immediately bailed out into a draw with with 17. Qf3 Bh2+ 18. Kh1 Bg3+ and perpetual. Carlsen rises up to the challenge of the gambits (which I like about him), but fails to survive the tactics (this time).

On the other hand, Carlsen is quite unbeatable in positional play. No one has positionally outplayed him for the longest time. As I've posted before <He builds up minute advantages like a juggernaut and grabs on small mistakes like a crocodile, irresistibly dragging his opponents into the swamp.> He has this 'swampy' style of play that sucks in even the strongest of today's GMs into the cloying mud. Had this game gone along quieter positional lines (say Bu did not essay the gambit, or if Carlsen had declined it), I would give Carlsen a 60% chance of winning sometime in the endgame. These positionally maneuvering Ruy and Italian positions seem to particularly suit his style.

Note that ALL the (five classical) games which Carlsen has lost this year were lost due to tactical mistakes or misjudgements in sharp positions. The same pattern mostly applies in the past decade. After having said that, one must note that Carlsen is one of the best tacticians in the world too. It's just that this is the only field where he can be predictably beaten.

The suggests something important for his would-be Challenger. Deploy the sharpest, but still sound openings, against the World Champion. Try to keep the middlegame double edged if such an option is possible. Try to decided matters before you reach the endgame. (This strategy actually worked for Kasparov against Karpov in their second match, so it's not without precedence.)

And if there are other options, do not play passively like this Carlsen vs Karjakin, 2017

Yes, with the understanding that human logic and silicon logic are somewhat different. Rd1 not only brings rook into the game, as you say, but gives the King a potential escape route via d2-c1.

Compare 16. Re2 in Capablanca vs Marshall, 1918>

I should have said <almost certainly> instead of <probably>. After all Capablanca, in a similar situation, did move Re2 in order to mobilize his rook.

More mind-boggling is this post from the Capablanca vs Marshall, 1918 page.

<Shajmaty: In 23 moves (between 14. ♕f3 and 36. ♗xf7+), Capablanca plays the best move (i.a.w. Stockfish) 21 times!>

Why?

1. That game is one of the most complicated double-edged and tactical games in chess literature. Virtually replicating the best computer lines move after move for two dozen moves in real time in such a game is almost inhuman. I doubt if any living master nowadays could do such a thing. We would be seeing lots of red moves live in the internet.

20 f4 disturbs the king side pawns. Instead of this 20 Bd2 connects the rooks.

22 Rxe3 helps to develop Black's rook. Instead of this 22 Bd2 connects the rooks.

You don't analyze, Ulhumbrus. You just select from your small stock of <My First Book of Chess Strategy> chesshomeric epithets:

"disturbs the kingside pawns without necessity"

"moves an already developed piece"

"connects the rooks"

etc.

click for larger view

Houdini 4

0:50-51 ;>D

[Fritz 10]: 1. e4 e5 2. Bc4 Nf6 3. d3 Nc6 4. Nf3 Be7 5. 0-0 0-0 6. Bb3 d6 7. c3 Be6 8. Re1 Qd7 9. Nbd2 [last book move] Rab8 10. Bc2 d5 11. h3 [11. exd5 Bxd5 12. Nc4 Bxc4 13. dxc4 Qxd1 14. Rxd1 Rbd8 ⩲] h6 [11 ... dxe4 12. Nxe4 Bd5 13. Bg5 ⩲] 12. exd5 [ ⩲] Nxd5 [12 ... Bxd5!? 13. Nxe5 Nxe5 14. Rxe5 Bd6 ±] 13. Nxe5 [ ±] Nxe5 14. Rxe5 Bd6 15. Re1 Bxh3 16. gxh3 Qxh3 17. Nf1 Rbe8 18. d4 [18. Bb3 Re6 19. Rxe6 fxe6 ⩲] f5 19. Bb3 c6 20. f4 [20. Bc4!? ±] Kh7 21. Bxd5 cxd5 22. Re3 [22. Re2!? Qg4+ 23. Kf2 =] Rxe3 [ ∓] 23. Bxe3 g5 24. Kf2 [24. fxg5!? f4 25. Qc2+ Rf5 26. Bxf4 Bxf4 27. Re1 ∓] gxf4 [-+] 25. Qf3 fxe3+ 26. Nxe3 Qh2+ 27. Kf1 Rg8 [27 ... Qxb2!? 28. Re1 Qxc3 29. Qxd5 -+] 28. Qxf5+ Rg6 29. Ke1 [29. Rd1 ∓] h5 [29 ... Kg7 30. Qd7+ Kg8 31. Qe8+ Kh7 32. Qf7+ Rg7 33. Qf5+ Kg8 34. Qc8+ Bf8 35. Qe6+ Kh8 36. Qe5 Qg1+ 37. Nf1 -+] 30. Kd1? [30. Rd1!? =] Kh6 [ ∓] 31. Nc2? [31. Rc1!?] h4 [31 ... b6!? makes it even easier for Black 32. Ne3 Qxb2 33. Rc1 Rg1+ 34. Nf1 -+] 32. Ne1 h3 [32 ... Qxb2 33. Rc1 Qxa2 -+] 33. Nf3? [33. Qc8 Rg1 34. Rb1 -+] Qg2 34. Ne1 [34. Nd2 there is nothing else anyway Qg4+ 35. Qxg4 Rxg4 36. Ke2 Rg2+ 37. Ke3 -+] Qg4+ 35. Qxg4 Rxg4 36. Nf3 [36. Ke2 desperation Rg1 37. Rd1 -+] Rg1+!! 0-1.

One drawback to being at the very top is how everybody wants to see you fall. Anyone who has ever been the highest rated player in a tournament knows the feeling, and of course for World Champion Magnus Carlsen that is a million times greater, with everyone out to defeat him. Then again, Xiangzhi is no slouch at 2710. The definitive game of the World Cup started as a Bishop's Opening which transposed into a Giuoco Pianissimo, then Black chose 4 ... Be7 over 4 ... Bc5. I don't get 9 ... Rab8 at all. After 18. d4 it is a very Marshall Gambit-like position with the crucial distinction that Black is down a piece. Time pressure played a major role in the ultimate outcome, yet that is part of the game.

The finish deserves a [DIAGRAM]:

click for larger view

37. Ne1 h2 & 38 ... h1=Q; 37. Nxg1 h2 38. Ke2 h1=Q, earning the coveted "!!" by Fritz.

Some insightful commentary:

<It's not often you see a Marshall Gambit within a different opening + a bishop sac on h3. Fascinating to see. From the resulting middlegame position black's gameplan is very clear and his position is much easier to play. I'm not surprised Carlsen crumbled in the resulting complications. He relies a lot on his intuitive feel for positions and that was a middlegame that required some extremely precise calculation.>

<h3 should never have even been played as this is a known sacrifice enabling plan with the Q and B battery. You can't allow that without resolving the position completely in your own mind first. He was truly shocked by the sac but not until Rbe8 that he thought he was in trouble IIRC and the move f5 was like a gut punch opening 6th rank for rooks and also preparing f4. He probably thought he was lost and was just kicking up dust after black gets in Qh2 it's hopeless. In the end the positional choices to leave a1 rook and so many pieces on the back rank so long made a bad position impossible to defend under time trouble and he collapsed.>

<It must be called a positional sacrifice in the first place: Black immediately obtains 2 pawns and opened enemy king. While it is a thematic matter in some lines of the Spanish, often White manages to bring his extra piece to the kingside, defend himself and emerge with a slight material advantage, in this game it was not clear whether 21-Re5 or 21-Bxd5, cxd5 22-Re5 was a better chance. But moves like 21-Re2, even though it was suggested by computers, are not understandable to a human mind.>

<Going back to Bu's dauntlessly courageous strategy for this game, I believe this again is another proof that it's the only way to play against Carlsen and still hope to win. Bu offers a gambit pawn, Carlsen as usual grabs it (he always does). Bu sacs a Bishop. Carlsen tries to retain the piece with 17. Nf1 when he could have immediately bailed out into a draw with 17. Qf3 Bh2+ 18. Kh1 Bg3+ and perpetual. Carlsen rises up to the challenge of the gambits (which I like about him), but fails to survive the tactics (this time).>

<Chessmusings> Great annotations!