What is the barest minimum a club player needs to know in order to play an opening?

Chessable’s course The London System: Essential Theory by IM John Bartholomew and FM Daniel Barrish aims to answer that question. Taking one of the most popular opening systems for White they attempted to create a repertoire that doesn’t require much memorisation and follows the “keep it simple” principle.

The London System as an opening has the major upside of White playing more or less the same moves against pretty much everything. It has however the downside of allowing Black to react in pretty much any way he likes.

The authors grouped the material based on Black’s set-ups. There are seven theoretical chapters, one chapter with model games and one chapter with tactics. The theoretical chapters are: …d5 without …c5, …d5 with …c5, Queen’s Indian Defence Setups (this basically means when Black fianchettoes the c8 bishop, as plans with and without …d5 are included here), King’s Indian Fianchetto Setups, Benoni Setups, the Dutch and Odds and Ends.

The London has the reputation of being a positional opening, but the authors took a different approach, trying to go for aggressive set-ups whenever possible. For example, against the Kingside Fianchetto set-ups for Black they recommend the move 3 Nc3 (after 1 d4 Nf6 2 Bf4 g6) and if Black plays 3…Bg7 they transpose to the Pirc by 4 e4. In this Pirc with a bishop already on f4 they go for the natural Qd2, 0-0-0 plan with kingside attack.

So the London can become a Pirc. It can also become other openings, as the authors do not remain contained in the typical Bf4, c3, e3 frame. In the Odds and Ends they also look at the Philidor Defence (via 1 d4 d6 2 e4 Nf6 3 Nc3 e5), some Benoni setups enter into Benko Gambit territory and so on. The London is so much more than only London.

But if it is so much more, how is the club player supposed to remember all that?

The authors solve this question by keeping the length of the lines up to approximately 10 moves. The longest variation I noticed was 17 moves long and it is the only forcing line in the repertoire. Naturally, keeping the lines short means that many things need to be left out, for example in the Philidor the line is 9 moves long and at that point theory only begins, but that is the point of the whole repertoire – it is supposed to be Essential and not In Depth.

Having learned the lines in this repertoire the club players can be confident when meeting any Black set-up against the London System. They will know how to develop their pieces and what their middlegame plans are. And that is all they need to know in order to obtain a good position before they start enjoying the process of playing.

The London System: Essential Theory is available on Chessable.