# London system move order

The standard London System consists of the setup moves: d4, Bf4, e3, Nf3, Nbd2, c3, Bd3. I'm wondering about the nuances of what the most accurate move order is to play it in. Here are some of my thoughts:

• Some people like reaching the London via 1.d4 Nf6 2.Nf3, but I like playing 2.Bf4; that way, you can go for the more aggressive setup with 3.Nc3 against King's Indian players, potentially tricking them into a Pirc.

• Against people who play symmetrically, ie. 1.d4 d5 2.Bf4 Bf5, I like playing an early c4 instead of c3 to break symmetry.

• If White plays Nf3 early, Black can play a combination of Nc6-Nh5 to harass / potentially trap the London bishop (since the queen has lost vision of h5) and force it to move off its natural diagonal, which can be annoying.

[FEN ""] 1.d4 d5 2.Bf4 Nf6 3.e3 c5 4.Nf3 Nc6 5.Nbd2 Nh5

• If Black follows the main line setup with d5/Nf6/c5/Nc6/Qb6, it seems more accurate to play Nbd2 before c3, in case Black decides to enter the sharp gambit lines with dxc5 / Qxb2.

[FEN ""]

1. d4 d5 2.Bf4 Nf6 3.e3 c5 4.Nf3 Nc6 5. Nbd2 Qb6 6.dxc5 Qxb2 7.Rb1
• In the main line, most masters seem to prefer the move order with d4-Bf4-e3-c3-Nd2; I'm not sure why this is.

[FEN ""]

1. d4 d5 2. Bf4 Nf6 3. e3 c5 4. c3 Nc6 5. Nd2

Why do masters prefer the above move order, and what other nuances am I missing from my points here?

• I'll just note that as a Pirc (but not KI) player I very much enjoy that transposition ... Make sure you understand it! Oct 9 '21 at 8:22
• Incidentally, I also play this move order although I played it at least a decade before the London System even got a name :-) (The most annoying thing with Bf4 is a Q attack on b2.) Oct 9 '21 at 10:14

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