What is xG?
Expected goals (xG) give every shot a value between 0 and 1: the chance a shot like it, from that spot and situation, is scored. Add them up and you get how many goals a side's chances were worth. Over a season, sides tend to drift back towards their xG, which is why a club well above its expected points is often heading for a correction. Expected assists (xA) do the same for the pass before a shot.
Expected goals data is Opta's, via Fantasy Premier League, kept match by match by My Football Facts. Updated twice a day. MFF's FPL picks use the same numbers.