The idea of sacrificing a pawn with ...b5 and ...a6 is quite old. Karel Opočenský applied the idea against, among others, Gideon Ståhlberg at Poděbrady 1936, Paul Keres at Pärnu 1937, Erich Eliskases at Prague 1937, and Theo van Scheltinga at the Buenos Aires Chess Olympiad 1939. Later, the game Mark Taimanov–David Bronstein at the Candidates Tournament, Zürich 1953, drew attention. Most of these games began as a King's Indian, with Black only later playing ...c5 and ...b5. Possibly the first game using the now-standard 1.d4 Nf6 2.c4 c5 3.d5 b5 was Thorvaldsson–Vaitonis, Munich Olympiad 1936.