"Xg [Expected goals]
Xg is a metric that examines EACH goal scoring opportunity of all players and HOW probable it is that a chance turns into a goal.
We take into consideration lots of factors such as the angle to the goal, the distance, how many defenders are in the way, etc. If Xg is = 0,76 , this means that there is a 76% chance that chance will turn into a goal [this is the case for a penalty]. If Xg is = 0,01, it means that there is only a 1% chance that this chance will turn into a goal. "