I don't know if the players at the London Chess Classic needed the Sofia rules to begin with, but if so they're working like gangbusters. Every round the games are long and hard-fought, and the overall number of draws has been relatively small. In round 5, as in round 1, all four games had a winner, and this time all four favorites won.
The biggest game was between the leaders by percentage, Michael Adams and Magnus Carlsen. Carlsen goofed in the opening with 13...d5, missing 14.cxb4! (Carlsen should have swapped on c3 first, and only then played ...d5.) The world's #1 had to defend for a long time, and with a bit of help from Adams managed to more or less equalize. Adams is only very rarely in time trouble, but he ran a little short of time near the end of the control, and it cost him. 38.Re3 was objectively alright but introduced a transformation of the pawn structure that could lead White into trouble, and two moves later - on the final move of the time control - trouble found him. 40.e4? was a major error, allowing Carlsen to reach a queen ending with an extra pawn and great winning chances, and as usual he cashed them in. That puts Carlsen to 4.5/5 (or rather, 13/15 on the tournament's 3-1-0 scoring system). Even more notably, it kicked his rating up to an almost absurd, video game-like 2860.5. The gap between Carlsen and the rest of the chess world is getting so large politicians may try to tax his rating to level the playing field and redistribute his points.
But don't feel too sorry for his closest pursuers, as they went forward as well. Vladimir Kramnik had a relatively easy time of things against Luke McShane, sacrificing an exchange for a terrific bind. Soon it turned into a raging attack, and it was remarkable that McShane managed to somehow avoid mate as his king raced safely from h6 to b8, and in time trouble, too. Unfortunately for him, his position remained lost, and after White's 49th move McShane resigned, five(!) pawns in arrears.
Viswanathan Anand completed the clean sweep of the English contingent, defeating Gawain Jones pretty easily on the black side of a 3.f3 Gruenfeld. Jones' opening choice was somewhere between perplexing and suicidal, as he went into an extremely sharp line played in game three of the Anand-Gelfand match - and without being properly prepared. Maybe he thought Anand wouldn't take over Gelfand's side of the opening, but he did. Jones's 14th move varied from the Anand-Gelfand game, but doesn't seem to have been preparation, as he spent more than 20 minutes on it. Anand sacrificed a pawn, and soon Jones completely lost the tactical thread. Anand was winning as early as move 18, and the remainder was a massacre. For those of you keeping track at home, that brings Anand's 2012 win total in classical games to three - one fewer than Carlsen has in this tournament alone.
Finally, Hikaru Nakamura got his second win of the event, at Judit Polgar's expense. Polgar didn't achieve anything on the white side of a Neo-Archangelsk Ruy, and was then outplayed in the middlegame into the ending. Maybe Polgar could have held after the time control, but she buckled under the pressure and fell under a decisive mating attack. The win keeps Nakamura in the hunt for a high place, while Polgar's tournament has gone as badly as Carlsen's has gone well: he has only given up one draw, and that's all that she has to her account. And as they play in the next round, one way or another their inverse symmetry will continue. Speaking of the next round...
Round 6 Pairings (Scores and the number of games played are in parentheses):