The London System is an opening system in chess characterized by the moves (with any first move by Black):
1. d4
2. Bf4
In addition to these moves, in the standard system, White supports the d pawn and bishop with a pawn on e3, the other bishop is developed to d3, the knights are developed to f3 and d2, and the d pawn is reinforced again by c3. However, some variation exists; for example, Nc3 can be played instead of c3, entering the Rapport-Jobava System (or Jobava London).
The system can be used against any virtually any Black response (although most popular against 1...d5) and thus comprises a smaller body of opening theory than many other openings. Black's most common response to the system involves playing c5 and Qb6 (pressuring White's now undefended pawn). White also has great flexibility in move order (2.Nf3 and then 3.Bf4 is common), and the system has many transpositionall opportunities. For example, White can transpose to the Queen`s gambit with c4 (instead of c3 or Nc3), and Black can transpose to the Caro-Kann Defence with ...cxd4 exd4.
White's set-up often results in a closed game, and often involves a plan to put a knight on e5, supported by the pawn and bishop. Although it has a reputation as a solid opening, the London System has been criticized for resulting in repetitive games and a lack of dynamic play. White can instead adopt a more flexible and theoretical approach after 2.Bf4, rather than committing to the same initial moves regardless of Black's response, often resulting in a more dynamic game.
Convert all the letters in the opening into numbers A=1, B=2... Y=25, Z=26 etc..
LONDONSYSTEM = ABCDEFGHIJKL
The cache can be found at:-
N55 (G-I)(G-B). (J-C)(L-K)(J-L)
W001 (B-A)(E-L). (C-F)(G-A)(J-E)