Chess Opening Theory/1. d4/1...Nf6/2. Bg5

=Trompowsky Attack= The Trompowsky Attack is a new offbeat opening with less theory which involves White immediately putting the bishop on g5 attacking the knight. Usually in most variations (2...Ne4 or 2...e6) Black avoids doubled pawns, but sometimes accepts them (2...c5 or 2...d5). The latter of each pair (2...e6 or 2...d5) just mentioned can transpose into the Torre Attack after 3. Nf3; however the Trompowsky Main Line (2...Ne4) typically doesn't transpose after it's played.In the Trompowsky Main Line, both sides move their developed minor piece twice: Black's knight from g8 to f6 to e4 and White's Bishop from c1 to g5 to f4. Afterward Black has many options to develop unlike many other openings. Some possible developing moves include c5, d5, d6, or e6.

A less common but also popular line involves 2...e6 (Classical Defense) when it is best not to trade pieces and instead develop naturally. This line can transpose into the Torre Attack with 3. Nf3 or continue with 3. e4 in the Trompowsky (Big Center Variation, which fits the position perfectly) and Black usually avoids the trade of minor pieces because of the pin (h6 and e5) and instead trades pieces directly with 4. Bxf6.

Even less common but transposable is the move 2...d5 which asks for a transposition into the Torre Attack (3. Nf3) or the Richter-Veresov (3. Nc3) but White can take advantage of the move and stay in the Trompowsky with 3. Bxf6, doubling Black's pawns.

Less common again is the 2...c5 line attacking the pawn. White can choose to push the pawn or trade pieces (3. d5 or 3. Bxf6). The former variation involves a "Poisoned Pawn Variation" which involves one side giving away a pawn for a opposing misplaced queen and a development lead. The variation goes 2...c5 3. d5 Qb6 4. Nc3 Qxb2.

There is also the move 2...c6!?, which is less commonly played, but nonetheless quite sound. This could lead to similar positions as the 2... c5 line, related to the poisoned pawn variation, or this can lead to 1. d4 openings, such as the Richter-Veresov Attack or even the QGD/Slav Defenses. This line also contains a trap: white must be careful and avoid 3. e3??, where 3...Qa5+ loses the bishop on g5 to a fork.

Theory table

 * 1.d4 Nf6 2.Bg5