Collen

Could anyone please elaborate on the Collen defense please, I would like to see some examples oif it being used and why it is one of the more prefered openings.

The diagram shows Whites set up using the Colle System. I omit the Black pieces because black can respond in many different ways. The light square bishop on d3 is central to the Colle System. This bishop can be a powerfull attacker against the enemy black king once castled kingside. On the otherhand, Whites dark square bishop on c1 is made bad because white has moved so many pawns onto dark squares, ie. b2,c3,d4,e3,(f2)(h2). Whites bishop on d3 aided by the knight on d2 and sometimes with Re1 or Qe2 intend to play the central push e3-e4. This move can open the position for the bishops which can be very strong against the black king on g8. The pawn can go as far as e5 and cut off blacks pieces from getting over to the kingside to defend from whites onslaught. In some lines White will need to pull of the 'classic bishop sacrifice' to execute a winning attack so white players should be aware of the rules for where/when this sac works. 

White can also play a stonewall setup but this puts more pawns onto dark squares and whites c1 bishop becomes more of a problem. All is not bad however as white can get a good space advantage and control strong squares. A Knight will usually go to e5 and the rook lift Rf1-f3-h3 (or g3) is always an option. Pushing pawns does create weaknesses tho!

To solve the bad bishop problem on c1 white can also play b3 insted of c3. When b3 is played the c1 bishop can make use of the c1-a3 diagonal and at any chance White can exchange this bishop in the middlegame i think he would be happy. The Colle System does not make too many appearance at top level but you will see it in ANY chess club you go to. If you want to avoid the problematic bishop on c1 you could try some related opening for white such as; The london system, Torre Attack, and The Trompowsky attack to some extent. I would suggest you try the Colle first and make your own decision.

This opening brought me great success at Junior National Level and would recommend it to anyone starting off because it is a 'set-up' to learn rather than opening theory as such.