Opening traps

London System Traps: 4 Real Traps for White and Black

The London System, 1.d4 d5 2.Bf4 or 1.d4 Nf6 2.Bf4, is known as a calm opening. But it has sharp traps, and many of them come from one fight: the black queen on b6 against the b2 pawn. Here are four real traps, three for White and one for Black. Each is on its own board with the side lines, and every claim was checked with Stockfish after the best defence.

8 min readPublished November 2026By Surajit Paul4 traps · 4 boards

▶ Start with trap 1 London System guide Queen's Gambit traps Practise vs bots

London System trap: 5.Nxd5! after 4...Qxb2? - the knight takes d5 and threatens Nc7+, White is winning (Stockfish +3.9)

In this article

Watch the traps (video)
The 4 traps at a glance
Trap 1: The poisoned b2 pawn
Trap 2: Nb5 and the c7 fork
Trap 3: ...Nh5?? and Qxh5
Trap 4: ...c4! against Bd3
Can Black trap the London bishop on f4?
FAQ

Watch: Stockfish 19 plays the London System

Before the traps, see the London in a real engine game from our Stockfish channel: Stockfish 19 against the new engine Crimson Sentinel. You can also replay that game move by move on our website.

The Most Boring Opening in Chess Became a Rook Sacrifice When Stockfish 19 Met a New Engine!! - video thumbnail — The Most Boring Opening in Chess Became a Rook Sacrifice When Stockfish 19 Met a New Engine!!

The 4 London System Traps at a glance

#	Trap	For	The mistake	Stockfish after it	What it wins
1	The poisoned b2 pawn	White	4...Qxb2?	Stockfish +3.9	The a8 rook
2	Nb5 and the c7 fork	White	4...e6??	Stockfish +3.4	The a8 rook
3	...Nh5?? and Qxh5	White	3...Nh5??	Stockfish +4.5	A knight
4	...c4! against Bd3	Black	5.Bd3?	Stockfish -1.0	The b2 pawn

How to use the boards: press ▶ Play or tap a move. The buttons above each board switch to the side lines (what if the other player plays something else). Arrows show the threats; draw your own with a right-click drag. The numbers are Stockfish evaluations after the best defence: + means White is better, - means Black is better.

London System traps for White

Three traps for the London player. Two come from the knight jumps to d5 and b5, one from the queen's road to h5. In each one Black plays a move that looks natural.

WHITE TRAPTrap 1: The Poisoned b2 Pawn (...Qb6 and ...Qxb2?)

1.d4 d5 2.Bf4 c5 3.e3 Qb6 4.Nc3Black falls for it with 4...Qxb2?5.Nxd5! - Stockfish +3.9

Black attacks b2 with ...Qb6. White does not defend it and plays Nc3. If the queen takes b2, the d5 pawn is left alone, and the knight takes it with the threat of Nc7+. Press Play, then try the side lines.

How to avoid it: as Black, after 4.Nc3 do not take b2. Play 4...e6 and keep d5 guarded. As White, answer 4...Qxb2 with 5.Nxd5!, not only 5.Nb5.

WHITE TRAPTrap 2: Nb5 and the c7 Fork (Jobava London)

1.d4 Nf6 2.Bf4 d5 3.Nc3 Bf5 4.Nb5Black falls for it with 4...e6??5.Nxc7+ - Stockfish +3.4

In the Jobava London the knight sits on c3. After ...Bf5 it jumps to b5, and the knight and the f4 bishop both hit c7. One careless move and the fork on c7 wins the rook.

How to avoid it: as Black, after 4.Nb5 guard c7 at once with 4...Na6 (equal game). A quick ...a6 early also keeps the knight away from b5.

WHITE TRAPTrap 3: ...Nh5?? and Qxh5 (the bishop hunt that drops a knight)

1.d4 Nf6 2.Bf4 d5 3.e3Black falls for it with 3...Nh5??4.Qxh5 - Stockfish +4.5

Chasing the London bishop with ...Nh5 is a real idea. But once White has played e3 and the f3 knight is not yet out, the queen on d1 looks straight at h5.

How to avoid it: as Black, play ...Nh5 only when a white piece blocks the d1-h5 road (a knight on f3, a bishop on e2) or when h5 is guarded. As White, after 3.e3 always check h5.

Traps against the London System (for Black)

For Black the best weapon is the same queen on b6. Against the London, the b2 pawn is often weak, because the bishop has left c1.

BLACK TRAPTrap 4: ...c4! and the b2 Pawn Falls (a trap for Black)

1.d4 d5 2.Bf4 c5 3.e3 Nc6 4.Nf3 Qb6White falls for it with 5.Bd3?5...c4! - Stockfish -1.0

A trap against the London for Black. White plays Nf3 before c3, so Qb3 is not possible. If White now plays the usual Bd3, the pawn push ...c4 kicks the bishop and the b2 pawn falls.

How to avoid it: as White, after 4...Qb6 deal with b2 first: 5.Qc1 or 5.b3 (both equal). Or play 4.c3 before Nf3, so that ...Qb6 can be met by Qb3.

Can Black trap the London bishop on f4?

Many players hope to trap the f4 bishop with ...Nh5 and ...g5. It almost never works. After 1.d4 Nf6 2.Bf4 d5 3.Nf3 Nh5 the bishop simply goes to d2, or to e5 and g3: after 4.Be5 f6 5.Bg3 Nxg3 6.hxg3 Black has the two bishops, but no extra material (Stockfish +0.3). And if the d1-h5 road is open, the knight on h5 is just lost (trap 3).

The real danger for White is the b2 pawn. A quick ...c5 and ...Qb6 is the sharpest answer to the London. Our London System guide shows the main plans against it, and the London, Trompowsky and Torre guide compares the London with the other Bf4 / Bg5 systems.

London System Traps FAQ

What is the most common London System trap?

The fight over the b2 pawn. After 1.d4 d5 2.Bf4 c5 3.e3 Qb6 4.Nc3, taking with 4...Qxb2? leaves d5 alone, and 5.Nxd5! threatens Nc7+. Stockfish gives White about +3.9.

Is there a London System trap for White?

Yes, several. The poisoned b2 pawn (5.Nxd5!), the Nb5 and Nxc7+ fork in the Jobava London, and 4.Qxh5 when Black plays ...Nh5 too early after e3.

Are there traps against the London System for Black?

Yes. After 1.d4 d5 2.Bf4 c5 3.e3 Nc6 4.Nf3 Qb6 5.Bd3?, the move 5...c4! kicks the bishop and Black wins the b2 pawn (Stockfish -1.0). If White castles or plays 6.Nbd2 instead of 6.Be2, ...cxd3 wins the whole bishop.

Is it safe for Black to take on b2 in the London?

Sometimes. It depends on the position: after 4.Nc3 in the 1...d5 line it is a mistake, because d5 falls. When White has played Nf3 and Bd3 too early, taking b2 is good for Black. Check what the queen leaves behind before you take.

What is the Jobava London?

A sharp London set-up with an early Nc3 (1.d4 d5 2.Nc3 Nf6 3.Bf4, or 1.d4 Nf6 2.Bf4 d5 3.Nc3). It is named after the Georgian grandmaster Baadur Jobava. The knight can jump to b5 and hit c7 together with the f4 bishop.

Can you trap the London bishop with ...Nh5?

Usually not. ...Nh5 can win the bishop pair, but the bishop has squares like d2, e5 and g3. And if White has played e3 before Nf3, the knight on h5 is simply taken by Qxh5.

Set these traps in your own games

Play the London System against a bot and see who walks into the c7 fork first.

▶ Practise vs bots Play Stockfish 19 All opening guides