Match of the Day using expected goals (xG) has really thrown the concept into the public eye but what is it? <br /> <br />When it appeared on the BBC programme during the first Saturday of the Premier League season, it left a lot of fans scratching their heads. <br /> <br />But it’s not an entirely new concept and is one way many statistical analysts use to assess a team’s attacking chances. <br /> <br />So with it now going mainstream, don’t worry if you are unfamiliar with what xG is, because we’ve got it covered. <br /> <br />Opta analysed more than 300,000 shots and a number of different variables to create the expected goals metric. <br /> <br />On a simplistic level, it is basically judging how likely a player is to score from a certain chance, putting a number on something a lot of people judge when watching a game. <br /> <br />And the latest edition in our Science in Football series should clear up any questions you have over expected goals. <br /> <br />Football Whispers’ James Lorenzo and Bobby Gardiner have looked at look at what exactly xG is, what goes into calculating it – including the speed of attack and the type of ball used to create the opportunity – and how you can understand the ratings?
