Chess Opening Theory/1. d4/1...d5/2. Bf4/Chess Opening Theory/1. d4/1...Nf6/2. Bf4/2...d5

= London System Main Position by transposition with ...d5 =

The Main Position of the London System, 1. d4 Nf6 2. Bf4 d5, can be reached via the Queen's Pawn Opening after 1. d4 d5 2 Bc4 Nf6.