London Grand Prix round 6, Peter Leko used a novelty in a well-known position in Najdorf variation of the Sicilian defence
LEKO - GIRI
Earlier players played only Qa5 here (this move number can differ as in the opening it is possible to repeat the position in quite a standard way Be3-Ng4-Bc1-Nf6). Leko offered a pawn sacrifice: 15.Kb1.
"I prepared this move three years ago before the Grand Prix tournament in August 2009 - explained Peter, - and at that moment I liked the idea. But since than a lot of time has passed and my computer shows this move in the first line so i think many players knew this move though. Perhaps there are games between computers or correspondence ones which we do not know, so I didn't look upon this move as a novelty really. So I didn't play like that against Wojtasek during the Olympiad. But as I expected Giri to play the Petrof defence which I analyzed during my day-off I was surprised to see the Sicilian and I decided to surprise him in my turn with this pawn sacrifice.
The only thing that was in my head was a key idea with 17.g3 and 18.f4. Computer variations with some advantage didn't seem to be successful while the play was promising, but my opponent reply 18...а5 turned out to be very good. Without this move white will gradually have a good position.
Giri: "I knew about 15.Kb1. I didn't remember my analysis but I rememeber that the computer tried to grab the pawn on d6 and that it was not at all serious so I thought this novelty isn't something special. Peter thought of an idea with 17.g3 and 18.f4 with position compensation which didn't seem at all simple so I decided to take a risk and make a strange move 18...а5. We both thought during the game that Peter missed 21.Bh6, winning exchange but in our analysis there was a lot of countergame for black so perhaps my move 18...а5 isn't too bad. My opponent decided to avoid principle variations and prefered to play securely. For example, 24.Qb7 was more ambitious, but if he prevents my game I prevent his so the drawish result seems fair".