Hello, could somebody please explain the relevance/importance of expected goals (xG)

How do you work out what is an xG and why do you bother? Aren't real goals (rG) the only thing that matters? Does it do more than judge your strike force (rubbish if they miss sitters and clever if they score tricky ones)? Why do I keep hearing about it as a thing?

Thank you 😊

Posted By: Bravo win or die, Feb 18, 14:47:36