But maybe its because we have neglected to post the actual line here, so

40.Rxa4 Ne3 41.b3 Rd8 42.Kg1 Rd2 43.Bh1 and nobody can figure out the clear win.

Now however, five minutes later a thousand engines find a unlikely sequence of King and bishop moves that suggest White can survive despite the rook infiltration, and despite appearances. 41 b3 Rd8 42 Kg1 Rd2 43 Bh1

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However, "In the old days" players rarely resigned till the move before mate. Had Mamedyarov continued a couple of moves, Bh1 surely would have occurred to him.

<Kaspablanca: i am amazed many kibitzers here HAVENT SEEN THE EASY CONTINUATION FOR BLACK!! If 41. b3 then Rd8!! is decisive, bear in mind that black can also move Kf7 to catch the knight.>

Wow, good thing you read the posts before deciding what they did and didn't have in them.

It would have been more interesting to us viewers if the Mame-Carlsen match had been continued rather than the Radja-Anand one.

I think there was a lot of life left in this here game after <41.b3 Rd8 42.Kg1 Rd2 43.Bh1> as suggested by Xaurus with his Rybka engine.

At this point there are some interesting deviations for move 43...*

It would be nice to know which way Carlsen would have gone at this junction. Rc2? Bxc3? Nd1 ?Rd1? I would assume that the 43....Nd1 line would be hardest for White to meet. Want to play it out?

<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.>

So Magnus says this is a win. Period.

<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.

Posted by: ComputoJon at January 12, 2008 21:03 >

By playing out the best moves for White and Black suggested by Rybka 2.3.2a, White's position simply steadily decreases.

I mean, just -look- at the position!

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Does anyone really think White can survive this?

<Does anyone really think White can survive this?

2760-rated Mamedyarov thought not and resigned while chess super-prodigy 2733-rated Magnus Carlsen agreed with Mamedyarov's assessment.>

Position after 40 ... ♘c4-e3 0-1?????:

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Hmm, well GM Marin says that the above position is -not- an obvious win for Black.

<White's decision to resign looks at least premature. I admit, his position does not look too appealing, but... nobody has ever improved his situation by resigning. Both players were probably convinced that the g2-bishop will be lost soon, but this is more of an illusion. After 41.b3 Rd8 White has 42.Kg1 Rd2 43.Bh1 when he is very much alive yet.

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Things would change if the black king could be activated quickly via g6 (and if Nf4, then ...Bxf4 gxf4 and ...Kxh4), but after 43...Kf7 White can question the stability of the enemy bishop with 44.Ra5 . Otherwise, White would play 44.Ra7, cutting the enemy king away and intending to advance of the a-pawn as far as he can, or exchange the dominating bishop with Ng7. 0-1. >

The point of 42 Kg1!! is that on 42...Rd1+ 43 Kf2 counterattacks the black N on e3. Mamedyarov may have overlooked that although he could not save his KB, he could make a counterattack on Black's N in return.

<Thus he liked his 11…c4!, gaining play on the queen’s side.>

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<Note that white cannot defend the extra c pawn, as if he was to try 13.Qd3 Rc8 14.b3 then black strikes with the strong 14…b5!.>

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In that position, what happens after the simple 43...Bxc3 (threatening 44...Bd4) 44. Nf4 Kf7?

45...Bd4 is still coming. White looks dead as a doornail. Am I missing something?

Here black has so many good moves available is not even funny:

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<Gnappo: In my opinion this is a draw... White can defend easily this position. f.e. 41.b3 Rd8 (that Kaspablanca defined "decisive") 42. Ra6 Ke7 43.Ra7+ Ke8 44.Kg1 Rd2 45.Bh1 White Bishop is safe, and Black King cannot leave the 8th rank.>

This is wrong - after 42 Ra6 Kf7 43 Ra7+ Kg6 44 Nf4+ Bxf4 45 gxf4 Kh5 46 Kg1 Re2 47 Bh1 Kxh4 the Black K goes to g3 and soon W is mated. And 43 Kg1 Rd2 looks too strong for Black.