This appeared at the end of the game Chelsea being 1.53 ours being 0.64

This is the explanation but I'm still confused!

"Expected goals" is a metric which assesses every chance, essentially answering the question of whether a player should have scored from a certain opportunity.

Put simply, it is a way of assigning a "quality" value (xG) to every attempt based on what we know about it. The higher the xG - with 1 being the maximum - the more likelihood of the opportunity being taken.

So if a chance is 0.5xG, it should be scored 50% of the time."

Apparently it means we wre very clinical?.

Any whiz kids - some teams got over 2.5. ...but 1 is the maximum??