Data analysts have studied the expected goals (xG) and expected goals against (xGA) of every Championship club so far this season, to evaluate the performance of teams by their attacking and defensive output relative to their expected rate.

xG and xGA are used to assign a value to goal scoring chances based on past performance data.

Comparing these values to actual goals scored and conceded can indicate whether a team is above or below average at taking or preventing goal scoring opportunities - or experiencing particularly good or bad luck around the goal.

In data compiled by BetVictor, it found that early Championship leaders Sheffield United are overperforming in both attack and defence by 23.39% and 55.39% respectively while Preston North End are the most underperforming team offensively (-112.54%), and most overperforming side defensively (90.64%)

Sheffield United top the table after 10 games - but which sides have over and under performed according to their xG and xGA? Picture: George Wood/Getty Images.

Blackburn Rovers are top of the league when it comes to goals scored above expected with 3.45.

Middlesbrough are the most underperforming team defensively having conceded 13 goals from an xGA of 7.67. Prior to their 0-0 draw with Rotherham, Boro had conceded the fewest shots of any Championship club but their defensive record was one of the worst in the league.

Bristol City have the highest xG of any team with 14.8, but are underperforming in defence having conceded 2.07 more goals than expected.

The full data for xG and xGA so far this season can be seen below...

How Sheffield United, Middlesbrough, Rotherham United, Hull City, Huddersfield Town, Sunderland and other Championship clubs have performed this season relative to their xG