The London System is a popular 1.d4 opening for White which has the reputation of being very solid. The London is considered a system because White can play the same basic setup for almost all of Black's responses. For this reason, the theory on the London is not as extensive as it is for other openings. White enters the London System when playing Bf4 before pushing a pawn to e3, usually through 1.d4 d5 2.Bf4. Note that the old mainline was 1.d4 d5 2.Nf3 Nf6 3.Bf4, but the current theory states that playing 2.Bf4 instead of 2.Nf3 is slightly more accurate. London System. The starting position of the London System. This opening's main idea is to create a solid pawn structure in the center by pushing pawns to c3 and e3, but only after developing the dark-squared bishop outside the pawn chain. Despite its being a solid opening by nature, the London also features aggressive lines and can catch Black off guard. Pros Hard for Black to get active play Difficult for Black to avoid A very sound way of getting a playable middlegame Cons Less chance of an attack It puts little immediate pressure on Black The Bf4 can be somewhat exposed Variations One of the advantages of the London System is that White will almost always play the same setup. Below are a few of the most common paths a London game can take: Mainline The London's mainline leads to a balanced position where White will usually go for an attack on the kingside. On the other hand, Black will play for a central break or a counter-attack on the queenside: 1. d4 d5 2. Bf4 Nf6 3. e3 c5 4. c3 Nc6 5. Nd2 e6 6. Ngf3 Bd6 7. Bg3 O-O 8. Bd3 b6 9. Qe2 Bb7. Indian Setup (...g6) One of the most common responses from Black to the London System is to play an Indian Setup, fianchettoeing the dark-squared bishop. Black puts a pawn on g6 to discourage White from developing the light-squared bishop to the active d3-square. White's most popular moves against this setup are almost identical to the mainline, except for the light-squared bishop developing to e2 instead of d3. 1.d4 Nf6 2.Bf4 g6 3.Nf3 Bg7 4.e3 A setup that has been gaining popularity over the past years is the Jobava London. White develops the b-knight to c3, where they would usually put a pawn, to give it a more active square. The Jobava London can turn into a much sharper game, and White can get a significant advantage if Black plays incorrectly. 1.d4 Nf6 2.Nc3 d5 3.Bf4 How To Play Against The London System If Black is familiar with how to face London System, there is not much White can do to create a significant advantage out of the opening. The mainline is an excellent way to equalize the game and create a balanced position. However, Black can try more testing lines that will force the White player to get out of their "comfort zone," notably: The Early c5 Black scores well in this line, winning 49% of the games, drawing 23%, and losing only 22%. The idea is to bring the queen out to the queenside with 3...Qb6, where White's dark-square bishop can't help. Black puts pressure on the b-pawn and the center, later fianchettoing their dark-squared bishop on g7. Jobava London A setup that has been gaining popularity over the past years is the Jobava London. White develops the b-knight to c3, where they would usually put a pawn, to give it a more active square. The Jobava London can turn into a much sharper game, and White can get a significant advantage if Black plays incorrectly. 1.d4 Nf6 2.Nc3 d5 3.Bf4
