Dee ihe ga-aga n'ihu na paragraf a - Echiche nke ịchụ aja na...b5 na...a6 bụ ihe ochie. Karel Opočenský tinyere echiche ahụ megide, ndị ọzọ, Gideon Ståhlberg na Poděbrady 1936, Paul Keres na Pärnu 1937, Erich Eliskases na Prague 1937, na Theo van Scheltinga na Buenos Aires Chess Olympiad 1939
Ọ dị mma. Ka oge na-aga, egwuregwu Mark Taimanov na David Bronstein na asọmpi ndị Candidates, Zürich 1953, dọtara uche. Ihe ka ọtụtụ n'egwuregwu ndị a malitere dị ka onye India nke Eze, na Black na-egwu...c5 na...b5. O nwere ike ịbụ egwuregwu mbụ jiri 1.d4 Nf6 2.c4 c5 3.d5 b5 bụ Thorvaldsson<unk>Vaitonis, Munich Olympiad 1936.