1. d2d4  1... g8f6  2. c1f4 [%cal dc1f4][%c_arrow c1f4;keyPressed;none;from;c1;opacity;0.8;to;f4;persistent;false] A much more dangerous move than it seems at first glance. This version of the London System, moving the bishop before the knight, is more flexible for White, keeping more options open. 2... d7d5  3. e2e3  3... c8f5  4. c2c4  4... e7e6  5. d1b3 A forceful move. If Black has to play something passive like b6 or Qc8, then White's strategy has clearly succeeded. The game move, developing the knight to d7, is only the fourth most popular choice, but it has been tried by strong grandmasters. A thematic and critical move is 5...Nc6. 5... b8d7  6. b1c3 