Canaries keeper Angus Gunn has been ranked bottom of the pile in the Championship for expected goals prevented so far this season.
According to an Opta statistic looking at all second-tier keepers to play 1,000 minutes or more this season, the Scotland international has conceded at least four more goals than he should have.
The metric subtracts the number of goals conceded by a keeper (in Gunn's case - 23) from his expected goals faced (where the relative shot quality of each on-target attempt is calculated and totalled; for Gunn it's 18.3).
That gives him an 'expected goals prevented' of -4.