London System: how to defeat copying moves? I played the London system for the first time today and encountered a problem in my second game (I won my first).

[fen "rn1qkb1r/ppp1pppp/5n2/3p1b2/3P1B2/5N2/PPP1PPPP/RN1QKB1R w KQkq - 4 4"]


What is the best response to black copying your moves in the London?
If you play the London then you have to be aware and ready for favourable transpositions to other openings like the Queen's Gambit, Slav, Barry Attack (John Nunn famously lost twice to Hebden against this and then complained bitterly that the derogatory name, "Barry Attack", just rubbed salt into the wound ;-), 150, etc.

This is such a case. Here, or even on the previous move, White should be looking to play c4 for a QGD variation where the black bishop is misplaced on f5.

Check out chapter 7 Symmetrical: 2...Bf5 and 3...Bf5 of "Win with the London System" by Sverre Johnsen and Vlatko Kovacevic for more ideas.