Expected assists (xA) measures the likelihood of any pass becoming an assist. Like expected goals (xG), xA is based on historical pass data. The pattern of play, where a pass is played from and received, and the type of pass are among the factors impacting the chance of a pass becoming an assist.
As with xG, passes are assigned an xA value between 0.01 and 0.99.
xA is a crucial metric for measuring how creative a player is, and much more useful than just looking at assists alone.
For instance, Bruno Fernandes led the Premier League for xA (16.7), though his actual return of eight assists showed huge shortcomings from his Manchester United team-mates when it came to finishing off those opportunities. Essentially, Fernandes finished last season with eight fewer assists than would have been anticipated based on the quality of chances he created.
And that’s the key difference when it comes to measuring chances created and xA. Chances created is a great way of measuring the quantity of opportunities a player tees up, whereas xA is a better indication of the quality of those chances.