The Colle System: the London's cousin that shuts a bishop in

The key idea

The set-up is fixed and there's one plan: prepare e4 with all the pieces in place, open the centre and free the c1 bishop exactly when the d3 bishop is aiming at the opposing king. If Black stops e4, the same set-up serves to push on the queenside with b4-b5. The scheme doesn't change; the plan does.

Example 1 · The set-up and the advance that justifies it

The scheme is nearly in place. White to move, and the whole opening consists of reaching one move.

1. O-O I castle with the scheme nearly built: d4, e3, Bd3, c3 and a knight on f3. Five moves I make almost every time, whatever my opponent plays. That's what playing a system rather than an opening means.
2. Be7 Quiet development from Black.
3. Nbd2 The knight goes to d2 and not c3, because on c3 I have a pawn holding d4. That's the detail that sets the Colle apart from almost everything else: the knight goes via d2 on its way to e4 or f1.
4. a5 He gains space on his wing.
5. dxc5 I trade here to get his c5 pawn out of the way. He'll win the pawn back with the bishop whenever he likes; what I take away is a centre with a gap to push through.
6. h6 He slips in a useful move before recapturing.
7. e4 And this is the move the Colle exists for. The whole set-up — bishop on d3, knight on d2, pawn on c3 — was there to reach this point: the centre opens, my d3 bishop aims at his king and my c1 bishop, shut in all game, finally breathes.
8. O-O He castles. A minimal edge, a fifth of a pawn, and that's the Colle's honest promise: it doesn't give you an advantage, it gives you a position you know how to play without having studied a thing.

Example 2 · The other plan: when Black stops e4

Black has put the bishop on d6, watching e5. If you can't push in the centre, push on the wing.

1. dxc5 His bishop on d6 watches e5 and complicates my usual plan. I start by trading on c5, which also makes him move that bishop a second time.
2. Bxc5 He recaptures with the bishop, as expected.
3. b4 And here I change plan without changing the set-up: if the centre won't open, I gain space on the queenside by shoving pieces along.
4. Be7 The bishop retreats.
5. b5 I keep pushing. Every advance takes a square from his c6 knight, which is the piece holding his centre.
6. Na5 The knight goes to the rim, where it's at its worst.
7. Qe2 I connect the rooks and put the queen behind the e3 pawn, already looking at e4.
8. a6 He questions my chain. A small but clear edge for White, a quarter of a pawn. Keep the idea that holds for every system: the set-up is fixed, the plan isn't. If your opponent blocks one plan, there's another — always from the same pieces on the same squares.

Practice

You're playing the Colle with White. Finish the set-up and reach the e4 advance, which is the whole point of the opening.

1. King safe with the scheme nearly built. In a system, this part isn't thought about. Put the king safe on the short side.
2. To d2 and not c3, because on c3 you have the pawn holding d4. The knight goes through there on its way to e4. Develop the b1 knight to the only square your own pawn leaves it.
3. You get his c5 pawn out of the way and open yourself a gap to push through. Trade on c5 before opening the centre.
4. The advance the Colle exists for: the centre opens, your d3 bishop aims at his king and the c1 one finally breathes. Push the pawn you've spent the whole game preparing.

The Colle and the London look so alike that the difference is worth keeping straight: the London gets the c1 bishop out before shutting its door and in return promises little; the Colle shuts it in on purpose and in return has a concrete attacking plan, the e4 advance with everything prepared. Neither gives an edge out of the opening, and both save you the theory. If you pick the Colle, remember the two things that make it work: the knight goes to d2 — not c3, which is taken — and the e4 advance is prepared, not improvised. And if your opponent stops it, you have the same set-up to push b4-b5 on the other wing.