lol at least some one can take a joke around here
defence is a art thats pretty hard to master, what i find best for me is to always switch to using one of the centre backs whilst using the x button (xbox 360) to call one of my midfielders back and apply pressure on the player on the ball. if you hold it long enough and he applys good pressure he usually wins the ball or knocks it on and then you just use you centre back to pick up any loose balls . When doing this properly it is really effective as your defence drops off and your midfield drop back to pressure your opponent (plus they dont usually concentrate on the dropping midfielder(s) as they automatically think you are not controlling him).
I dont know what you mean by jockeying but i think your talking about applying pressure with the player your controlling by holding down the a button. This is not really effective as it is easily read and all the opposition have to do is turn you