Effectiveness of 'Opposition Instruction'?

[vearn]

I would like to know if there's certain type of opponent player that should have specific instruction towards them. Example like, player with high pace should have close down instruction on them.
What will show onto foot do?And how effective is opposition instruction in a match? Does using it disrupt player instruction in my tactic?
The reason I'm asking mainly because frustrated with David N'gog with just average attribute just dribble through Evra, Jones and Ferdinand in 1 run..even when I'm playing Man City, he keep doing that to all my top defense like a child play even when I'm reloading save again and again. :'(

 

[havanaclue]

Show onto weaker foot and hard tackling will not affect your formation but closing down and tight marking will pull players out of position.
Check out this site Opposition Instructions - Guide to Football Manager 2012. Gives good general insight to the game.