ECO code: D04
Colle: 3...Bg4
Moves: 1. d4 d5 2. Nf3 Nf6 3. e3 Bg4
This variation of the Colle System features Black developing the dark-squared bishop to g4 early, pinning White’s knight on f3. The move 3...Bg4 is characteristic for putting immediate pressure on White’s knight, aiming to challenge White’s setup before White completes their typical Colle development.
From Black’s perspective, this move is somewhat provocative and attacking, as it tries to disrupt White’s smooth development and may induce weaknesses or concessions in White’s center and kingside structure.
For White, this setup remains largely positional and solid, focusing on building a strong pawn center with e3 and d4. The opening does not directly attack the center with the bishop move, but the tension created by the pin can influence center control and piece placement.
Overall, while Black’s 3...Bg4 does not immediately contest the central pawns, it indirectly challenges White’s control of the center by targeting a key defender (the knight on f3) and can lead to dynamic play.
This opening is defined by the position shown on the board below. The moves displayed are a typical sequence that leads to it, but different sequences can reach the same position and still carry the same opening name.
Practice puzzles and train your tactics with real positions from games that used the Colle: 3...Bg4, and sharpen your opening mastery.
Puzzle 1 of 11 - Move #7 white