I am retiring my London System now (mostly), moving on to other d4 openings now. 

My favorite GMs to study are Petrosian, Steinitz, Philidor, and Karpov. I am very interested in improving my positional understanding in chess. Sometimes I switch back to a more sharp tactical opening, but when I do I usually try to add in the new things I'm learning with positional imbalances into the aggressive tactical play. 

"Let us say the game may be continued in two ways: one of them is a beautiful tactical blow that gives rise to variations that don't yield to precise calculations; the other is clear positional pressure that leads to an endgame with microscopic chances of victory.... I would choose [the latter] without thinking twice.” - Anatoly Karpov

I was playing chess with my friend and he said, ‘Let’s make this interesting’. So we stopped playing chess.