London or Catalan, Which is Best?

Starting the game with 1. d4 is thought to be a more positional approach than playing 1. e4. It's easier to pick a system after 1. d4 and consistently play similar setups with the white pieces. Two of the most popular systems are the London System and the Catalan. Opening. To see a detailed comparison, check out this post titled Why I Dropped The London System and post your thoughts in the comments below. 

London vs Catalan - Which is best?

Your Thoughts?

Which system do you prefer as White? Which is easier to play against as Black? Leave your comments below!