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Corus 08 r1: The Mighty Have Fallen

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When I said in my preview that I thought Anand might have a tough time I wasn't thinking about round one. It's a little early for fatigue to be setting in. But Teimour Radjabov just beat him in a tough 2R vs R+B endgame (not Anand's strong suit, as a side note) after another adventure in the Anti-Moscow Semi-Slav. Magnus Carlsen won with black against Mamedyarov and Aronian beat Topalov. Mamedyarov played an insipid g3 closed Sicilian but probably shouldn't have lost. He got into time trouble and fell apart. It was early to resign and some of the afritzionados insisted that White's position wasn't even worse. Carlsen said afterwards that he was sure he was winning. A computer might find a way to grovel on for a while without losing a piece to a rook infiltration, but it's long-term ugly.

Topalov played his usual brilliant dynamic chess to get a plus after surprising Aronian with the Grunfeld. But the Bulgarian has always been better off sacrificing the exchange than winning it. He tightened up and White had full compensation with the mighty knight on d4. It was still hard to imagine Topalov losing but he declined to swap rooks White got a lot of play. (21..Rac8 was suggested by GM Christiansen on Chess.FM.) A topsy-turvy slugfest between two of last year's co-winners. The third of whom, by the way, beat Anand with the white pieces. It looked like the world champ had weaseled his way out of opening difficulties with the ..Qf4-d2 trick, but Radjabov found a nice queenside mating idea that led to the win of the exchange. We were 50-50 on whether or not White should win the endgame. Eventually he worked his king up to f6 for the victory. Impressive technique and it will be interesting to see how well Anand defended. He often loses patience in defending technical positions but this one may have been hopeless from the start.

So the world champ and the world #3 lost today, and the youngest participant won with black. The other four games had less action than a Merchant Ivory film about sloths. It looked like Kramnik had great chances with white against van Wely but he allowed a queen trade and then decided there was nothing in the endgame. Strange. van Wely worked as Kramnik's second in Mexico City but there's no mercy at this level when you have a 180-point rating advantage. Adams-Gelfand was a short Petroff draw. Sad to see such a great Najdorf player doing so well with the Petroff. Ivanchuk passed up an opportunity for an interesting exchange sac and quickly ended up with no advantage against Polgar. The draw offer was a little obnoxious, however, since the board was still full of pieces. Leko equalized easily against Eljanov's listless play but decided not to play for more, accepting another short draw.

As usual, there was plenty of excitement in Groups B and C. Short looked lost in 16 moves against Harikrishna, apparently blundering 16.Qe4. The Indian played enterprisingly instead of greedily and got three pieces for his queen and a withering attack. (20.Qf5 was the consensus crusher for White.) Short failed to wither, however, and things really got messy. LarryC suggested an early h4 for White to open up the h-file for his rook. In the game Black got a pair of rooks of the board and enough play to force a draw. All seven games in the C Group were decisive. Unfortunately that included a loss by Irina Krush. Top seed Caruana won with black to get off to a good start.

More tonight when I've had a chance to actually look at the games. Official site. Many other coverage links in yesterday's item.

Kudos to today's New In Chess / Chess.FM trivia winners Trebejo, Siddhu, and Murkes (one year of NIC). Respectively, they were the fastest to answer: 1) What is the average age of the Group A field? 2) After the Netherlands, which country has the most total representatives in groups A, B, and C? 3) Of all the participants in the history of Group A, who is listed first, alphabetically by last name?



Isn't Hou - Bacrot drawn in the final position?

maybe the scoresheet of Hou - Bacrot is wrong as 76... Ke5 is a major blunder allowing white to draw. I presume 76...Ke4 was actually played.

76...Ke5 is most likely a digital board error. At the end of the game you put both kings on the central dark squares to indicate a win for Black (so the next "move" would have been 77.Kd4, which of course isn't registered since it's illegal). This kind of mistake is quite common; usually it's pretty obvious, sometimes much less so. I'm slightly surprised nobody seems to have implemented a way round it yet.


I'm rather convinced in Mamedyarov-Carlsen that Rybka was correct in the eval of = to -/=. It's just because computer programs these days are designed to take long term positional factors into effect, and Rybka especially. It doesn't mean it wasn't a tough position, but I'm betting there was some trick for white that was saving the game. If computers mis-evaluate, they're more often being too optimistic, instead of the other way around. Great broadcast by the way!

Had Mamed continued Carlsenn would have outplayed anyway.

I just spent quite a bit of time on Mamedyarov-Carlsen with Rybka 2.3.2a. In the lines that I tested, I played Rybka's suggestions for White and Black. In all cases, the assessment steadily deteriorated for White into a complete loss.

From the human point of view (I'm a master but obviously the Corus players are vastly stronger) it looks very difficult for White. His Bishop and Knight are simply bad, and his Rook isn't doing much. Meanwhile, Black's Rook penetrates and his pieces dominate the board.

But strictly from Rybka's point of view, the assessment goes down-down-down for White as you play through the recommended lines.

ComputoJon - thanks, that's much more interesting than the average Fritz Says X commentary. :)

Heh, computers and long-term positional factors. Nice in theory, but extremely limited in practice and completely subordinate to material values, by necessity. Even Rybka's programmer says it has a 1600-level understanding of such things, if I recall. (Maybe it was 1800.) Computers still must think linearly, unable to see move five without seeing moves one through four. Unless they can reach the position in search depth it doesn't exist. This is why positional factors like domination and long-term plans involving forced transitions to simple endgames often aren't evaluated correctly by computers.

Critical risk factors like passed pawns get exceptional treatment but beyond that the computers are okay with white in that game simply because they don't see to a loss of material from the final position. But if you sit there and hit your space bar and let the computer play it out against itself it will eventually get to black winning, of that I have no doubt.

By the way, didn't Anand miss a repetition draw claim against Radjabov?! The position is identical after black moves 57..Kf6, 59..Kf6, and 63..Ra7 (instead of 63..Ra8). Holy heck.

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    This page contains a single entry by Mig published on January 12, 2008 1:28 PM.

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