Colle with 3...Bg4 Opening and Middlegame
In order to study better the transition from the opening into the middlegame I am going to create a series of posts involving my opening repertoire. This inlcudes Colle, QGA, and Pirc. To start is the line I have seen the most often, the Colle with 3...Bg4. I believe this line is easier to deal with in my opnion than it's cousin 3...Bf5.
Our line starts 1.d4 Nf6 2.Nf3 d5 3.e3 Bg4 there are now two branches both of which work 4 c4 and 5. Qb3 or h3. I'm not going to follow every opening sideline but look at the types of middlegame strategy that are likely to develop. This line is with Qb3 c6. Black has two basic options to exchange on f3 or not. The development of the two positions can go as follows
As white I prefer the non-exchange on f3 version a little more since the ideas for white are clear in the structure.
The backward pawn on c6 offers several options. It can allow the knight to settle into an outpost on c5. White can als pressure the pawn up the c-file. Trading queens, if black allowed it would make things easier. Black can castle and is a little ahead in development but after Bd3 Rb8 Qc3 white still looks just a little more pleasant.
However, I think in this line black should actually play Bxf3 and the resulting position looks more interesting but also challenging for white.
White has to be careful with the h-pawn and the king will never be really safe. I do like to play for Rg1 g2 Rhg1 bringing pressure up the g-file. Black can counter with g6 since it's hard for white to take advantage of the weak f6 square. White also can play for e4 and perhaps e5. Bd3, e4 opens up the dark squared bishop. Of course white's king is his other major problem along with weak pawns. For black the best plan is to get castled and then prepare to advance with b5. If white slows down with a3 and f4 black should have good chances.
These posts are not just to share my ideas but also to learn, so let me know your comments. In part 2 I will look at the Bg4 with 4.c4 at blacks responses e6 and dxc4. Then I will look at white coming right out with 4...h3