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

Accelerated London system Indian defence A46, A48 2. Bf4 · Accelerated London system (Indian defence) White develops their dark-squared bishop, so that they may play e3 to support the d4 pawn without leaving the bishop stuck behind the pawn chain. This is the London system, a general set of moves for White that can be played against a variety of moves by Black (it is Accelerated insofar as White has played Bf4 before Nf3). Thus, 2. Bf4 can be played against both 1. d4 d5 and 1. d4 Nf6. For an introduction to the Accelerated London system, see the move order 1. d4 d5 2. Bf4. After 2...d5, the most common reply, the two move orders (1. d4 d5 2. Bf4 Nf6 and 1. d4 Nf6 2.Bf4 d5) merge. Then, Black's main approaches are 3...c5 or 3...e6. By virtue of having not committed a pawn to d5 yet, however, in this move order Black has a number of other approaches: 2...g6, playing King's Indian-style with ...Bg7, ...d6 and ...c5. 2...b6, to play Queen's Indian-style with ...Bb7, ...e6, ...Be7 and ...d6. Playing both ...g6 and ...b6 to play in a Double fianchetto-style. 2...c5: after 3. e3 Qb6 Black wishes to target White's weak b2 pawn as soon as possible. In any case, White generally plans to play e3 and c3 to support the d4 pawn, Bd3, and Nf3 then Ne5. An alternative set-up involves Nc3 instead of c3, the Jobava-Rapport London system. Theory table . References London System Chess Opening Crash Course: The London System Win with the London System. 2005. Sverre Johnsen, Vlatko Kovačević. 1-9046-0035-2. __NOTOC__