"I just got good"
From the excellent Mechanic's Institute Newsletter #472:
Bobby Fischer facts:
His USCF rating was 1726 on the May 20, 1956 list
2231 on May 5, 1957
2626 ( # 2 behind Reshevsky) March 1958 .
I am remined of the answer Bobby gave to a question concerning how he became so strong so quickly: "I just got good."