How to crush "London System" ??

WilliamShookspear

After 9...Rg8, Stockfish gives 10.Ne5

godsofhell1235

If white is playing c4 it's going to be some kind of queen's gambit line.

If you're staying in the london, the pawn will go to c3.

Black has many options, of course.

Against low rated players who are playing out of fear of knowing nothing about chess, this works pretty well. I don't know proper theory for it

 

godsofhell1235

This is the way I learned first. First 4 moves almost always the same. 5th move almost always Qb6.