Possession
From Hattrick
Possesion is very important within Hattrick. You'll gain more possession from playing MOTS or when your midfield is better then your opponent's midfield.
You'll lose possession from playing PIC or playing with certain tactics.
The more possesion you have, the more scoring opportunities you will get.
At Hattristics you can find a table where the average hometeam possession is shown with each combination of midfield strengths at.