Better than average.

(idiomatic) A hypothetical average or generic individual; the common man (or person, by extension).

(ergodic theory) The average (if it exists) of a function over iterations of T, a measure-preserving transformation on a measure space, starting from some initial point x.

Worse or lower than average.

plural of batting average

(statistics) One of a family of techniques used to analyze time series data, in which a weighted average is determined for a given data point based on its value and the past values.

(statistics) The statistical tendency toward a fixed proportion in the results when an experiment is repeated a large number of times; the law of large numbers.

(baseball) A statistic which compares the total number of bases achieved by a batter over that batter's number of at bats.

An arithmetic mean of values biased according to agreed weightings.

plural of average Joe