Lev Polugaevsky (1934-1995) was one of the strongest players in the world from the late 1960s until the early 1980s. He was the originator of the meticulous opening study style Kasparov was later on to perfect and bring to great heights.In a bruising 1980 candidates' match against Viktor Korchnoi, Polugaevsky scored a valuable win with a powerful opening novelty against the Queen's Indian Defence (1. Nf3 Nf6 2. c4 b6 3. g3 e6 4. Bg2 Be7 5. 0-0 Bb7 6. d4 0-0) that involved a pawn sacrifice with 7. d5!? - a line that subsequently was given the stamp of approval by Kasparov and christened the 'Polugaevsky Gambit'.