Trompowsky attack is a queen’s pawn opening that starts with 1.d4 Nf6 2.Bg5. White’s idea is to exchange bishop for knight to give black double pawns. This can be a good surprise opening to play against club players.
Main drawback of Bg5 move is that b2 pawn is left undefended too early and as we will see, black can take advantage of it. Here black has a lot of options.
Black plays 2…d5
After 2…d5, white can play 3.Nc3 or 3.Nf3 with a positional game. But the main line in the spirit of the Trompowsky is 3.Bxf6. Black can capture with either pawn. Most popular line is 3…exf6 4.e3 Bd6 5.c4 dxc4 6.Bxc4 0-0 7.Nc3 c6 8.Nf3 Nd7 9.Qc2 f5
Exercise: What happens if white plays 10.Qxf5?
Here it seems like f5 pawn is hanging. But 10.Qxf5? is a blunder due to the tactic 10…Ne5! And black wins a piece. So the main move is 10.0-0 Nf6 with a positional battle ahead.
Black plays 2…c5
After 2…c5, white has again two options. White can play either 3.Bxf6 or advance the pawn with 3.d5.
White plays 3.d5
After 3.d5 Qb6 black attacks the weak b2 pawn. Here the main line involves sacrifice of b2 pawn with 4.Nc3 Qxb2 5.Bd2 white is threatening Rb1 and then Nb5. So black has to go back 5…Qb6 and after 6.e4 d6 7.f4 white has a very strong center as compensation for the sacrificed poisoned pawn.
White plays 3.Bxf6
After 3.Bxf6 gxf6 (exf6 is also possible) 4.d5 Qb6 (again attacking weak b2 pawn) 5.Qc1 f5 6.g3 Bg7 7.c3 d6 8.Bg2 Nd7 9.Nd2 Nf6 10.Nh3 h5 and we reach following position.
Black’s last move is instructive, which gets rid of an isolated pawn with the idea of h4. Black has two bishops and on the other hand white has a strong pawn on d5. Position is about even.
Black plays 2…e6
The idea of 2…e6 is to discourage Bxf6 since now it is defended by the queen. But at the same time knight on f6 is pinned. So white here has a possibility of playing 3.e4. After 3…h6 4.Bxf6 Qxf6 5.Nf3 d6 6.Nc3 Nd7 7.Qd2 a6 (Stopping the annoying Nb5) 8.0-0-0 Qd8 9.h4 b5
In this line black managed to get two bishops advantage without having doubled pawns which is a plus point. On the other hand, his pieces are a bit underdeveloped and white still has a good control over the center.
White can avoid playing 3.e4 and simply go for 3.Nf3 h6 4.Bh4 c5 5.e3
Black can again choose to harass b2 pawn with 5…Qb6 or play simply 5…b6 6.Nbd2 Bb7 7.c3 with a positional game ahead.
Black plays 2…Ne4
This is the strongest refutation for the Trompowsky attack. Attacking the bishop right away and forcing it to retreat without giving any concessions. White can play either 3.Bf4 or 3.Bh4. 3.h4 is also possible move.
White plays 3.Bf4
The main line after 3.Bf4 goes 3…c5 4.f3 Qa5+ 5.c3 Nf6 6.d5 Qb6
Again, we see the move Qb6 occurring in many lines, attacking the weak b2 pawn. The line goes 7.Bc1 e6 8.c4 exd5 9.cxd5 c4 10.e3 Bc5 11.Kf2
As we see, white has to play some odd moves to fill up the holes in his position. But it is playable since white has a strong center.
White plays 3.Bh4
After 3.Bh4 c5 4.d5 Qb6 5.Qc1 g5 6.Bg3 Bg7 c3, Black has a beautiful move here 7…Qh6!
Black is threaterning to play Nxg3 and white can’t capture with the h pawn because the rook on h1 would hang. So white has to play either 8.Nh3 or 8.Bxb8. It doesn’t feel good to play like this from white side. So it is apparent that black should be happy with the opening outcome.
Game Played with Trompowsky attack
Here is classic game played between Romanov, Evgeny (2619) vs Svidler, Peter (2760)
Conclusion
The main idea of Trompowsky attack is to create a dynamic balance by giving up a bishop for double pawns. Black can either allow that or play 2..Ne4 and put a direct question to white’s opening choice. The main drawback is the weak b2 pawn which black can attack with Qb6 in most of the variations. From white side, Trompowsky is a good occasional choice. It can work as a surprise. But at the same time, if white is not comfortable sacrificing the b2 pawn, then white should avoid playing early Bg5.