Accelerated London System

The Accelerated London System is the most direct route into the London System: White develops the dark-squared bishop on move two, before playing e3. With the bishop already outside the pawn chain, White can follow with e3, c3, Nd2, Nf3 and Bd3 without boxing it in. White's standard scheme hardly changes whatever Black does, so move orders are largely interchangeable. At higher levels the London is more often reached through 2. Nf3 Nf6 3. Bf4, which keeps the bishop's commitment back a move. Engines judge the position as balanced, and it is one of the most frequently reached named positions on Lichess.

The resulting games are usually closed. A typical White plan is to post a knight on e5, where it is backed by the d4-pawn and the f4-bishop, and to aim pieces at the kingside; against a castled king the sacrifice Bxh7+ followed by Qh5+ is a recurring motif. The early bishop move also has a cost: b2 loses its protection, and much of Black's counterplay targets that pawn.

2...Nf6 is the most popular reply, after which Black chooses between ...c5 and ...e6. In the ...e6 lines Black plans ...Bd6 to castle quickly and offer a trade of White's London bishop; if White retreats to g3, an exchange there gives White the half-open h-file after hxg3. Black's light-squared bishop often struggles to find a good square, and the structure resembles a Semi-Slav with colors reversed. A kingside fianchetto with ...g6, ...Bg7 and ...O-O is less frequent, and White typically answers with h3 to keep h2 available for the bishop. 2...Nc6 is the second most common reply, and White's results against it are the best among the main lines. The Steinitz Countergambit, 2...c5, aims for ...Qb6 and ...Bf5 ahead of kingside development, increasing the pressure on b2. White generally declines 3. dxc5, the Steinitz Countergambit Accepted, and prefers c3, leaving Black to exchange on d4 while White keeps two pawns in the center; ...cxd4 exd4 can lead to a Caro-Kann structure. Black scores better against 2...c5 than against the other main replies. The rare 2...h5 sets a trap for 3. e3.

The move 2. Bf4 appears as early as Jacob Sarratt's 1808 treatise, in a line continuing 2...Bf5 3. Nc3 Nc6 4. f3. James Mason introduced the e3, Nd2 and Bd3 scheme at Vienna 1882, and the name derives from the London tournament of 1922, where Capablanca was among those who used it. The system is a favorite of amateurs and is often criticized for repetitive play, yet Ding Liren won with it in game six of his 2023 World Championship match against Ian Nepomniachtchi. Combining Bf4 with Nc3, the Rapport–Jobava London, is the main modern alternative, using the knight and bishop against c7 and preparing an early e4.