Chess Opening Theory/1. d4/1...Nf6/2. c4/2...e6/3. Nc3/3...Bb4/4. Bg5

Nimzo-Indian Defence E30-E31 4. Bg5 · Leningrad Variation White decides to match Black pin for pin, and the e4 square is once more a no man's land. More subtle is the fact that Black's knight no longer controls d5 either. For that reason, van der Sterren calls the d5 advance "the point but also the necessary consequence of 4. Bg5."Fundamental Chess Openings Paul van der Sterren 2009 Gambit Publications Ltd Bracknell 978-1-906454-13-5 72 Either /4...h6/ 5. Bh4 c5 6. d5 or /4...c5/ 5. d5 h6 6. Bh4 is almost always played. 4. Bg5 is a fairly uncommon move against the Nimzo-Indian, being only played by 2% of Masters on the lichess opening database. With no black pawn on d5 White isn't threatening to win it like they often are against the Ragozin or Queen's Gambit Declined. References Nimzo-Indian Defence