15-year-old Teimour Radjabov beat Garry Kasparov in the second round in Linares. (Both are from Baku, Azerbaijan.) It was easy for chess writers everywhere (myself included) to say that he was the youngest player ever to be a world number one. Not that we did any research, mind you, but it's hard to imagine anyone else coming even close. I can only think of three possibilities: Reshevsky, Fischer, and Arturo Pomar.
Fischer had his chances. At 15 he drew a game with Tal in the 1958 Portoroz Interzonal and beat Larsen in the same event. He was 16 when he added victories against Smyslov and Keres. Fischer was already 18 when he finally got wins against Tal and Petrosian. Radjabov may retire by then.
"Arturito" Pomar of Spain was quite a prodigy himself. He also had the chance to play several games against the ailing Alekhine in the champion's final years in Spain. One of these was a draw when Pomar was just 13 years old. (Gijon, 1944). According to Alekhine's own notes to that game, Pomar was a move away from winning and instead played for a draw. Of course Alekhine was far from being the best in the world by then.
The famous win by the 11-year-old (although his age has been disputed) Sammy Reshevsky over Janowsky in 1922 is a worthy contender for most impressive win by a youth even if he was 13 and not 11.
