This way of starting the game has long since shed its image as an opening for amateurs, world class players like So, Kramnik, Grischuk, Vachier-Lagrave, Aronian and Karjakin play the opening with both colours, and included in the basis for the London Book there are also 126 games by Magnus Carlsen. In order to guarantee a high degree of reliability in the statistics a threshold for the acceptance of games and parts of games was set at 2300. Thus the Powerbook is based on 263 000 engine games and also 32 000 games from Mega 2021 + Correspondence Database 2020.
One of the basic positions of the London System occurs after the most frequently played moves by both sides: 1.d4 d5 2.Nf3 Nf6 3.Bf4 c5 4.e3 Nc6 5.Nbd2 e6 6.c3 Bd6 7.Bg3 0-0 8.Bd3 b6 and is presented in the following image:
What strikes the eye is the move 9.e4!?’s statistics. The early opening of the centre is actually not quite in the spirit of the London System, but of course its success is justification for White. But perhaps you prefer to study the modern variation 5.Nbd2 Qb6 6.dxc5 Qxb2. Here the Powerbook offers you statistics based on more than 18 000 games – here human theory has to be content with 450 games.