Wijk aan Zee, Round 8: Carlsen Regains the Lead

Magnus Carlsen has reclaimed the clear lead after eight rounds of the Tata Steel Chess Tournament, thanks to yet another characteristic example of the power of persistence. Carlsen, like no one else today and few (if any) in history, is able to keep creating problems for his opponents for hour after hour after hour. Today's victim was Sergei Karjakin, who with Black was fine after 20 moves, was fine after 40 moves, and was probably fine (but on the defense) after 60 moves. Finally, on move 68, faced with a complicated choice, Karjakin went wrong, and finally had to resign after 92 moves. Karjakin had been just half a point back, but now his chances for first have taken a serious hit.

Of course, Carlsen's chances are even stronger than they were coming into the round. He had been tied with Viswanathan Anand, and as Anand had White against Ivan Sokolov it looked like the champ was in great shape. He has a big plus score against Sokolov, the white pieces, a much higher rating and had been in much better form. Yet despite all that, and despite Sokolov's choice of opening (or maybe because of it? He played a sideline of the Schliemann/Jaenisch, of all things) Anand got nothing from the opening and offered a draw after his 24th move.

Anand is half a point back, and Levon Aronian and Hikaru Nakamura are a further half a point behind. Aronian won with startling ease after Hou Yifan's error on move 24 and outright blunder on move 25. As for Nakamura, he was on death's door throughout much of his game with Loek van Wely, but dogged defense saved half a point. (60...Bc2!! was especially nice.)

In other games, Fabiano Caruana defeated Erwin L'Ami, while the games Harikrishna-Leko and Giri-Wang Hao were both drawn. All the day's games (with notes to four of the games) can be replayed here. As for the round 9 pairings, they follow, with player scores in parentheses. Note that Monday is a rest day; round 9 will be played on Tuesday.

• Sokolov (2.5) - van Wely (3.5)
• Leko (4) - Anand (5.5)
• Karjakin (4.5) - Harikrisha (4.5)
• Hou Yifan (2.5) - Carlsen (6)
• L'Ami (2.5) - Aronian (5)
• Wang Hao (3.5) - Caruana (4)
• Nakamura (5) - Giri (3)

In Group B, there's a three-way tie for first: Richard Rapport, Sergei Movsesian and Jan Timman (!!) all have 5.5 points; Arkadij Naiditsch has 5. Timman's performance is noteworthy both because of his age - he's 61, by far the oldest player in all three groups - and because he has the highest TPR of any of the Dutch players! The most successful Dutchman in Group A is van Wely, with a TPR of 2692. Timman's is 2753.

In Group C, the two-horse race is again even, with Fernando Peralta and Sabino Brunello sharing first with 6.5 points apiece; David Klein is a point back.

Wijk aan Zee, Round 6: Carlsen In Clear First

It's too soon to crown Magnus Carlsen the (Group A) winner of the 2013 Tata Steel Chess Tournament, but with his third win in his last four games he has taken the clear lead after round 6; seven rounds remain.

Carlsen's win came against Ivan Sokolov, whose fortunes are fading fast. Sokolov was fine out of the opening, but as often happens against Carlsen, he was outplayed a little at a time and was lost after the first time control. Carlsen did make a mistake late in the game, but Sokolov didn't catch it and regular service was resumed.

Either Viswanathan Anand or Sergey Karjakin could have kept pace with a win, but both players drew (comfortably, with Black). Anand had slightly the better of things in a complicated game against his countryman Pentala Harikrishna, while Karjakin drew very comfortably with Black in a Berlin against Fabiano Caruana.

Hikaru Nakamura - Erwin L'Ami was also a comfortable draw for Black, while Anish Giri-Hou Yifan was still another success story for the black pieces - except that she earned a full point. She thereby escaped the cellar (Sokolov dwells alone there) and caught up with Giri.

The other two games were won by White. Loek van Wely won his second straight game with the white pieces, thanks in part to a probably dubious pawn sacrifice by Wang Hao. Van Wely accepted the pawn and the resulting queenside majority, and was able to use it while snuffing out his opponent's kingside ambitions. Finally, Aronian won his second straight game, this time over Peter Leko. The players reached a Marshall Gambit-like ending where White had a bishop and knight and a 2-1 queenside majority against Leko's bishop pair. (Both sides had three kingside pawns.) The particular Marshall ending this resembled is now basically a dead draw at the GM level, but Aronian had some small trumps in the game version. It should have been a draw in any case, but it was tougher and Leko failed to save the game.

The games can be replayed here (with varying levels of annotation); meanwhile, here are the pairings for round 7 (as usual, player scores are in parentheses):

• Anand (4) - van Wely (3)
• Sokolov (2) - Harikrishna (3.5)
• Leko (3) - Carlsen (4.5)
• Karjakin (4) - Aronian (3.5)
• Hou Yifan (2) - Caruana (2.5)
• L'Ami (2) - Giri (2)
• Wang Hao (3) - Nakamura (3.5)

Finally, a little update on the B- and C-groups, which are qualifiers for the groups above them. (In other words, the B-group winner gets an automatic invite to next year's A-group, and likewise for the C-group winner with respect to next year's B-group.) Richard Rapport leads the B-group with 5 points, a full point ahead of Arkadij Naiditsch, Daniil Dubov and Sergei Movsesian. The C-group has two leaders at the moment, Sabino Brunello and Fernando Peralta, both of whom have 5 points. David Klein is a point behind them.

Carlsen the Norwegian "Name of the Year"?

Chicago voters ("Vote early and often!") and those bored of supporting Psy against Justin Bieber can go here if they want to engage in a ballot-stuffing operation to make Magnus Carlsen the Norwegian "Name of the Year". He's currently in second place, but I'm sure that once the broader chess community knows about this his success will be a foregone conclusion. (HT: Martin Thoresen.)

London Chess Classic, Round 2: Carlsen, Kramnik Win Again, Break Rating Barriers

Nothing is official until the tournament is over, but the unofficial news after round 2 of the 4th London Chess Classic deserves notice. With his win over Levon Aronian, Magnus Carlsen has (unofficially) pushed his rating to 2855.7, breaking Garry Kasparov's all-time rating record of 2851 and equalling (when rounded up) Kasparov's retroactively calculated unofficial peak of 2856. In the process of winning, he has also pushed his lead over Aronian to a whopping 51 points on the live rating list.

His partner in the lead is Vladimir Kramnik, who defeated Hikaru Nakamura with the black pieces. He too accomplished something noteworthy in pushing his rating back over 2800. He has also moved close to the number two spot on the rating list - the next extra half-point he gets relative to Aronian will do the trick.

Now for a brief recap of the games: Aronian sacrificed a pawn in the opening against Carlsen but seemed to misplay it, after which Carlsen, with White, had very good winning chances. Aronian dug in very well and at one point may have even been better, but when he failed to react properly to Carlsen's pawn advances on the kingside the tables turned again, and White won with a nice breakthrough combination in the end.

Against Nakamura's unusual Scotch with 6.Qe2, Kramnik seemed to come out of the opening in very good shape, and in due course won a pawn. It took a lot of work for him to convert the advantage in a queen ending, but he was up to the task and brought home the full point.

Viswanathan Anand had the white pieces against Luke McShane, but he was soon much worse. Only dogged defense and a bit of luck enabled him to escape.

Finally, Judit Polgar enjoyed a material advantage against Gawain Jones on the white side of a Sicilian Dragon, but Jones somehow managed to keep just enough counterplay to prevent Polgar from consolidating. After yet another long, hard fight, they too agreed to a draw.

Round 3 Pairings, with scores (3-1-0 system) in parenthesis:

• Aronian (0) - Anand (1)
• Kramnik (6) - Carlsen (6) (The Big Game!)
• Jones (1) - Nakamura (3)
• Adams (3) - Polgar (1)
• McShane - Bye (+ commentary)

Mexico City: Play Carlsen Now (Updated)

The chess festival in Mexico City is a full show - not only is there the four player knockout event with Magnus Carlsen, Lazaro Bruzon, Judit Polgar and Manuel Leon Hoyos; there is also a Carlsen vs. the Rest of the World game underway right now. You can join in the fun through the website.

As for the knockout event, Carlsen won his sem-final against Bruzon, beating him with White in the rapid game and drawing (with some difficulty) in the blindfold with Black. Tonight, Polgar will play Leon Hoyos.

UPDATE: Carlsen won the game, which was pretty exciting:

[Event "CarlsenVsWorld"]

[Site "Mexico City, Mexico"]

[Date "2012.11.24"]

[Round "1"]

[White "GM_Carlsen"]

[Black "The_World"]

[Result "1-0"]

[WhiteElo "2848"]

[Opening "Sicilian: Najdorf, Adams attack"]

[ECO "B90"]

[TimeControl "7200+0"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. h3 e5 7. Nde2 Be7 8.

g4 O-O 9. Ng3 Nbd7 10. Nf5 Nc5 11. Bg2 Be6 12. O-O b5 13. a3 Rc8 14. f4 Na4

15. Nxa4 bxa4 16. g5 Nd7 17. Nxe7+ Qxe7 18. f5 Bc4 19. Rf2 f6 20. g6 h6 21.

Be3 Nc5 22. Rd2 Rfd8 23. Qe1 Qb7 24. Rad1 Qxb2 25. Rxd6 Rxd6 26. Rxd6 Qxa3

27. Qd2 Nd3 28. Rd7 Bb5 29. Rd5 Nf4 30. Rc5 Re8 31. Rc7 Qa1+ 32. Kh2 Kh8 33.

c4 a3 34. cxb5 Qb2 35. bxa6 Qxd2 36. Bxd2 Ne2 37. Rc4 a2 38. Ra4 1-0

The Best Advice Carlsen Ever Got

"I should break new barriers all the time". That was the advice Simen Agdestein (one of Magnus Carlsen's early trainers and a great player in his own right) gave Carlsen when he was 10, and seems to have been understood by Carlsen as advice to play new openings and new positions. (The full quote is here - HT to Michael Bagalman.)

What was good advice to one person may not be so for another, and while it surely helped Carlsen your mileage may vary. Further, too much opening hopping can lead to a player's being incompetent in a wide range of openings! For most of us, though, it is good advice: it helps us keep fresh and expand our knowledge, and as a fringe benefit it also frustrates those looking to prepare for us.

Carlsen Wins Final Masters In Blitz Playoff Over Caruana

The Final Masters came to a conclusion today, and Magnus Carlsen won - deservedly - against Fabiano Caruana in a blitz playoff. Both players finished with +3 scores, each losing only one game in the event - to each other. Caruana went +3 in the first cycle and even in the second, while it was the reverse for Carlsen. So why do I say Carlsen was the deserved winner, when both players had such similar results?

The answer came in today's round, before the blitz games. Both Carlsen and Caruana had Black, against Levon Aronian and Francisco Vallejo, respectively. Carlsen drew with Aronian, but he had to sweat a while, as Aronian enjoyed a definite and nagging edge for a long time in a very old-fashioned Queen's Indian. Nevertheless, once he equalized, even though he had no legitimate chances to win at all, he played on a bit longer when Aronian offered a possible repetition. He took chances early in the game, in the hopes of reaching a position where he could fight for a win, and then even later fought when there was practically nothing left to fight for.

Contrast that with Caruana's game. Caruana is a big specialist in the Neo-Archangelsk variation of the Ruy, but chose instead to play the Zaitsev. Trying to avoid some preparation? Maybe, but he wasn't worried about that earlier in the event, even though he's aware that every professional on the planet knows he plays the line. Anyway, Vallejo shamelessly played the Ng5-f3 repetition, daring Caruana to choose a different system. Not particularly admirable on Vallejo's part, but when you're -4 and just turned what could have been 2.5 points (on classical scoring) the past three rounds into a single half a point, wanting to put an end to the event is pretty natural. But why is Caruana giving him a break? Vallejo isn't a bad player, but he's not doing well and he's the lowest-rated player by a considerable margin. If you're not going to play for a win against the bottom marker by rating and score, who are you going to play for a win against?

Viswanathan Anand and Sergey Karjakin played a lively draw in a sharp line of the Slav, and so the final standings (not counting the tiebreak) looked like this:

1-2. Carlsen, Caruana 17 (on 3-1-0 scoring; their "real" score was 7-3)
3. Aronian 11 (5-5, with one win and one loss)
4. Karjakin 10 (4.5-5.5, with one win and two losses)
5. Anand 9 (4.5-5.5, with one loss)
6. Vallejo 6 (3-7, with four losses)

On to the blitz (4' + 3") playoff. Carlsen had Black in game one and played the Berlin Defense. Carlsen managed to artificially isolate White's e-pawn and win it, and he subsequently converted his material advantage in a rook ending. The second game was a bit of a farce. It's very difficult to win on-demand with Black - especially against Carlsen - so Caruana probably felt the need to play a riskier and somewhat unfamiliar opening. Carlsen played somewhat untheoretically as well, but clearly had a better feel for the opening:

1.e4 c5 2.Nf3 e6 3.g3 b6 4.Bg2 Bb7 5.Qe2 d6 6.d4 cxd4 7.Nxd4 Nf6 8.0-0 Nbd7 9.Rd1

Here White is threatening a standard trick that more often arises from the g3 line against the Taimanov/Paulsen. Caruana either didn't know it, didn't suspect it, or just grossly underestimated it. (Ironically, he made a similar mistake against me in a blitz game a couple of years ago, and was extremely fortunate to draw - I had a winning position and he had no material, but I ran out of time.) Black needed to play something like 9...Qc7/Qc8/Qb8; instead:

9...a6? 10.e5

and now another big error:

10...Bxg2? 11.exf6

Black is completely lost. If 11...Bb7, 12.Nxe6 finishes the game, but after

11...Bh3 12.Qh5

was curtains. (If 13...Bf5 14.Nxf5 exf5 15.Qe2+/15.Re1+ followed by 16.fxg7 and 17.f4 wins a piece.) Caruana kicked on for five more moves (12...Qxf6 13.Qxh3 Be7 14.Nc3 Qg6 15.Nc6 Ne5 16.Nxe7 Kxe7 17.Bf4) and called it a day.

Bilbao, Rounds 6 & 7: The Magnus Monster is Back

After the first cycle in Sao Paulo, Magnus Carlsen looked like an also-ran - lucky to be in clear third place, "only" five points behind the leader, Fabiano Caruana. Two rounds into the second cycle, in Bilbao, he and Caruana are tied for first, and he's not far from catching Garry Kasparov's all-time rating record. (Prescinding from any possible rating inflation, anyway.)

All the non-Carlsen games in the second cycle of the "Final Masters" have been drawn (just three more Viswanathan Anand will keep his title!), but the Norwegian terror is again working his magic. In round 6 he had the white pieces against Caruana, and this was pretty close to a must-win game for him. He rose to the occasion, and in his usual style: a semi-theoretical opening (the King's Indian Attack vs. the French, in this case), using the middlegame to induce some enemy weaknesses, which leads to persistent pressure in the ending followed by the opponent eventually cracking. Check, check and check. Caruana maintained material equality for a long time, but the bishop ending they finally reached was hopeless. Curiously, it was a sort of mirror image of Fischer-Keres from Zurich 1959. There the players had light squared bishops, and Fischer had the only two pawns, on the f- and h-file. In Carlsen-Caruana, they ultimately reached an ending with dark squared bishops and white c- and a-pawns! In both cases the only real task was to prevent the defender from sacrificing his bishop for the bishop-pawn (the f-pawn in Fischer-Keres; the c-pawn in Carlsen-Caruana), and the winners coped in both games.

Then today, Carlsen had White again; this time against rating tail-ender Francisco Vallejo Pons. Once again Carlsen left the beaten tracks of opening theory most expeditiously, meeting today's French Defense with 4.exd5 against the Winawer. That isn't a completely theory-free zone, but Carlsen avoided most of that theory as well. The difference between this game and yesterday's is that Vallejo didn't make it to an endgame. Carlsen maintained pressure against Black's kingside, and eventually broke through and won.

Here are the pairings for round 8, with scores (remember, 3-1-0 scoring) in parenthesis. There are three rounds to go:

Karjakin (5) - Carlsen (12)

Anand (7) - Caruana (12)

Vallejo (4) - Aronian (9)

The Daily Update: London & Sao Paulo/Bilbao

Two super-tournaments at once! Of the top 18 players on the Live Ratings list, all but five are busy in either London or Sao Paulo/Bilbao (the first cycle is in Sao Paulo, and then they'll shift over to Bilbao for part two).

We're up to round 4 in London, and it was a good day for two of the three G-stars, as Gelfand and Grischuk won their games. (Giri only drew.) In Grischuk's case, it was the result of a classy win over Mamedyarov. Playing a slow system in the Ruy with d3 (it has become all the rage these days, avoiding forcing lines and making Black play chess rather than demonstrate preparation), Grischuk built up a nice space advantage and then sacrificed a piece for three very good pawns. Soon Mamedyarov gave the piece back for those same three pawns - or rather, for three different pawns. White's passed c-pawn was the most important pawn on the board, and to eliminate it Mamedyarov wound wind up two pawns down in a lost rook ending, and so he resigned.

Gelfand's battle with Wang Hao took a different course. With White in a Catalan, Gelfand came out of the middlegame with an extra pawn and good winning chances. In his view (see the interview at the official site, linked above), the chances of a win or a draw were about 50-50, but Wang Hao defended resourcefully and finally reached a drawn ending. In the end, there was one last problem to solve, and 55...Kf8 would have solved it! Instead, apparently forgetting about White's pawn on f4, Black played 55...Kh7?? and resigned after 56.Kf7, as mate cannot be stopped (56...Kh6 doesn't help as 57...Kg5 is not a legal reply to 57.Rh1#).

So with his second win, Gelfand reclaims the sole lead he enjoyed after round 1. There's still a long way to go, and only after tomorrow's round will the players pass the halfway point. Here are the pairings, with the players' scores in parenthesis:

Round 5 Pairings:

• Topalov (2) - Leko (2.5)
• Dominguez (2) - Nakamura (2)
• Wang Hao (1.5) - Kasimdzhanov (1.5)
• Mamedyarov (2) - Gelfand (3)
• Ivanchuk (1.5) - Grischuk (2.5)
• Adams (2) - Giri (1.5)

Now to Sao Paulo, for round 1 of the first leg of this double-round robin tournament. Two of the three games were decisive: one very speedily, the other an entirely long, drawn-out affair. Aronian sprung some nice preparation on Karjakin he had been holding on to for a long time. After White's 18th move in a comparatively lively Queen's Indian (at times analogous to a "speedy snail"), Aronian was up the exchange for a pawn, but Karjakin had counterchances on the long a8-h1 diagonal. It seems that there were little improvements available for both sides along the way, but the key moment came after Aronian played 23.f3. Here Karjakin had an attractive equalizer - one he saw, too, but apparently in a slightly different position. The key move was 23...Nd3!!, when after 24.Rxd3 Qxc4 Black is down a rook for a pawn, but White's king is in a world of trouble. The greedy 25.Re3 loses after 25...Ba6! 26.Ne2 Qc2!, when White cannot save the knight with 27.Kf2 because of 27...Bc5. Instead, 25.Rd8 improves, but this is only enough for equality after 25...Ba6 26.h4, leaving Black nothing more than a perpetual check.

Instead, Karjakin's 23...Nd7 took the heat off, and after 24.Ne4 Qa4? the game was lost; the passive 24...Qc8 would have allowed Black to keep resisting. I'm not sure what Karjakin missed, but after 24...Qa4? 25.Rxd7 Bxe4 26.Rd8 White's king was safe while Black's was not, and the game was over a few moves later.

Viswanathan Anand played his first official game since retaining his world championship title against Gelfand several months ago, and he kicked off the tournament inauspiciously, drawing with White against Vallejo Pons. In fact, he even managed to come out of the opening with an inferior position, but by the end of the game, many moves later, he obtained a purely symbolic edge when the draw was agreed.

Finally, Caruana-Carlsen was an epic struggle that went more than 90 moves and saw both players take turns pressing for a win. Carlsen tried the Winawer French, and his reward was a lousy-looking position as soon as move 14. It didn't just look bad; it was bad, but when Caruana failed to take advantage (e.g. with 16.Bxg6 hxg6 17.Rh3 +/-) Carlsen gradually took over the game.

Surviving the opening took a lot of time, though, and as the first time control loomed Carlsen started to squander his advantage. Most commentators, and the players as well, criticized first 31...Nxe3, and then the plan with 34...h5 and 35...g4. That series of moves took Caruana from a sure loss in the long run to a highly defensible fortress in an opposite-colored bishop ending. Carlsen is nothing if not persistent, however, and he spent the next several hours trying to breach the fortress. Looking for a way in required a lot of thought, though, and when he decided on move 76 to avoid a perpetual by tucking his king away on h2, he was short of time and almost down to the 10-second per move increment.

It was at this point that Caruana decided to go for it with 77.cxb4 Rxb4 78.Rxe6 Be4 79.Rxe4!? The sac may not have been 100% sound, but it was incredibly dangerous for Black, and with almost no time to solve the problems Carlsen was in serious trouble, practically speaking. The computer expresses some skepticism about Caruana's sacrifice (80...Rb2!!, for instance, may be winning), but it took just two moves for everything to go upside down. Carlsen's 80...Kg2 was very natural, but it threw away the (hard to find) win, and then after 81.Ke3 Black had to play either 81...Rb1! or the flashy 81...Rb3+(!!) to hold the balance. Instead, he chose the wrong time for ...Rb2, and after 82.d5! he was lost. His 86...h4 was a terrific try, but Caruana responded perfectly and won the game.

A brief comment: Few things in sports/competition bother me as much as seeing a player defeat himself. It drives me bonkers when I do that - and as a result I think I do it relatively rarely. But this is not really such a case, to my mind. Of course the loss could have been avoided - Carlsen could have offered a draw (well, could have acceded to a repetition; draw offers are forbidden in the tournament) at practically any time from move 30 on, and it would have been accepted before his vocal cords stopped vibrating. But he was always better, and was always justified in continuing. Playing 76...Kh2 entailed risk, yes, but it was a reasonable risk, and self-respect as a professional also entailed continuing the fight. He lost this game, but this fighting attitude has and will garner far more wins in the long run. So rather than apportioning blame to Carlsen or offering some idiotic comment to the effect that he was unlucky, I would rather give full credit to Caruana (send him back, especially as he practically never lives in Italy anyway!). He didn't get discouraged after blowing a serious advantage, but fought on forever, and after five or six hours of play had the gumption to fight not just for the draw but for the win! Well done.

Round 2 Pairings: Vallejo - Carlsen, Karjakin - Caruana, Anand - Aronian.

Biel 2012, Round 2: Carlsen, Bacrot Win; Carlsen, Giri Lead

So far, so good for the 2012 edition of Biel: the games have been full of excitement and youthful energy. That's not surprising in a tournament where 24-year-old Hikaru Nakamura is in the graybeard half of the table.

Speaking of Nakamura, he drew again today. He was pressing throughout against Anish Giri in a Catalan-turned-Bogo-Indian, but the youngster (youngerster?!) held and maintained a share of the lead.

The battle between Etienne Bacrot and Alexander Morozevich was a bit mysterious at one moment, at least to me as an online spectator. Bacrot was White in a Marshall Gambit Slav, and in a well-known theoretical position after 9...Qxg2 he thought for about 45 minutes - at least if the relay on ICC was correct. (There weren't any delays with the transmission of the other games, so that shouldn't be the explanation.) His response after that deep think (or brief nap) was the conventional one. Ironically, Morozevich's reply to 10.Qd2 was the very unusual 10...e5; 10...Nf6 is standard. (In Ruslan Scherbakov's book The Triangle System, he spends 12 and a half pages on 10...Nf6, and says only this about Morozevich's move: "10...e5!? followed by ...Bf5 might be playable though.")

Bacrot's natural reply 11.Bxe5 was already a new move, and the position grew incredible sharp. Seriously analysis of this game would take some time, but what is clear is that 21...Ba6 was a fatal error; Black needed to bravely play 21...bxc6 and hope that White had nothing better than 22.Qxa7 Rxd6 23.Qa8+ Kc7 24.Qa7+ Kc8 25.Qa8+ etc. He doesn't seem to. After 21...Ba6? Bacrot landed some nice blows: 22.Ng5! Nxg5(?) 23.Bd7+! Kxd7 24.Qe7+ Kc6 25.Qc7+ and Black preferred resignation over allowing 25...Kb5 26.Qc5+ Ka4 27.Qb4#.

Magnus Carlsen vs. Wang Hao was a 4.Qc2 Nimzo-Indian with a quick e4. They were in new territory pretty quickly - 8.d5 was a new move in what was already a rare position - and it was soon clear that the battle would be between Black's structural advantages and White's initiative and attacking chances. After 16...h6 the spectators were looking with bloodlust at ideas like 17.Bxh6, but that appears to be inconclusive: 17...gxh6 18.Rhg1+ (18.Qd2 will transpose) Kh8 19.Qd2 Nh7 20.Qxh6 Rf7 leaves White with sufficient compensation after 21.Qxd6 or 21.Re6, but not more than that.

So Carlsen kept squeezing, but maybe he could have played Bxh6 on move 21. Again, he preferred to keep up the pressure, and on move 22 he induced an error. Wang Hao should have played 22...Nh5, aiming to further activate one or both of his knights and maybe swapping off a White attacker or two. Instead, his 22...Nxd5? gave Carlsen what looks like a good opportunity, even if he chose not to play it: 23.Bxc5 bxc5 (23...Rxf5? 24.Bd6 or 24.Bd4 is crushing) 24.Be6 Nf4 25.Bxf7 Nd3+ 26.Kb1 Rb8+ 27.Ka1 Qxf7 28.Rxg7 Qxg7 29.Rxg7 Kxg7 30.Qa4 is not an ending Black should draw.

But Carlsen chose 23.Bd4, which while probably not as good certainly maintained a pleasant advantage. (23.Bxh6 was also possible.) A few moves later he gave up his rooks for Black's queen and g-pawn, and with his very strong bishops Black's position was hard to play; indeed, he was soon in something pretty close to zugzwang. His last chance to keep the ship sailing, at least for a little while, was with 31...Rh7. After 31...Rfe7? the loss was guaranteed and speedy, and Black resigned after a forcing sequence culminating with 35.f4 because after 35...Rf5 36.Bxf6 Rxf6 Black's king and rook are parted by 37.f5+ Ke5 38.f4+.

So Carlsen joins Giri in the lead, and pushes his unofficial rating to the verge of 2840. Here are tomorrow's pairings, with player scores given in parentheses. Note that the totals are based on 3-1-0 scoring:

• Wang Hao (3) - Nakamura (2)
• Morozevich (0) - Carlsen (4)
• Giri (4) - Bacrot (3)