Openings · A45

Trompowsky Attack

The bishop comes out on move two and asks the knight a question before Black has chosen a defence at all.

1.d4 Nf6 2.Bg5played as White

The idea

2.Bg5 sidesteps everything: no King's Indian, no Grünfeld, no Nimzo-Indian, and none of the theory that comes with them. White either takes on f6 to double the pawns and play against them, or keeps the bishop and builds an ordinary game a move ahead of Black's preparation.

It is genuinely sound rather than a trick, but it is sharp in the way gambits are: several of the critical lines are short, forcing, and lost on the spot by whoever has not seen them.

Practise the line

You play White; the other side answers on its own. Nothing here is saved or graded.

Your move 1 of 20/2

1.d4Nf6
2.Bg5

Your move. Drag a piece, or tap it and then its square.

Common mistakes

Three that come up again and again below master level. Each is ordinary opening theory — a named trap, or the error every coach corrects — not a statistic, and not drawn from anybody's games.

Retreating to h4

1.d4 Nf6 2.Bg5 Ne4 3.Bh4 c5 4.f3 g5

The mistake: Keeping the bishop with 3.Bh4 and then challenging the knight with f3.
Why it costs: 4…g5 wins a piece: 5.fxe4 gxh4 leaves the bishop with nowhere it could have gone. The bishop on h4 is short of squares from the moment it retreats there, and f3 is exactly the move that traps it.
Instead: 3.Bf4, which keeps the bishop on a diagonal it can leave, or 3.h4 first if you want to keep the tension on the kingside.

The f3 push, one move early

1.d4 Nf6 2.Bg5 Ne4 3.Bf4 c5 4.f3 Qa5+

The mistake: Playing 4.f3 against 3…c5 without a plan for the check.
Why it costs: 4…Qa5+ 5.c3 Nxc3 is the trap the line is famous for — the knight cannot be taken, because 6.Nxc3 Qxc3+ forks king and rook, and Black comes out ahead with White's king still in the middle.
Instead: 5.Nc3 rather than 5.c3, which is the move order that makes the whole idea safe, or 4.d5 and 4.Nf3 keeping the game normal.

Doubling the pawns for nothing

1.d4 Nf6 2.Bg5 e6 3.Bxf6 Qxf6

The mistake: Trading on f6 as a matter of course, because doubled pawns look like a permanent gain.
Why it costs: Black recaptures with the queen, which is now developed, and has the two bishops in a position with no fixed weaknesses. Doubled f-pawns are only a target if the position stays closed enough to attack them; here it does not.
Instead: 3.e4 — the sharpest line in the whole opening — or 3.Nd2 and e4 next, taking the centre while the bishop still ties the knight down.

Try it on one of your own

The board above is for the line itself; this is for a game you played. Paste a game in this opening, or pull one from chess.com, and every move is graded against what the engine would have played. Open the board, read how the grading works, or go back to the other openings.