xBA
Expected batting average — what AVG should be from quality of contact.
What xBA means
Statcast translates each batted ball's EV/LA into a hit probability. Big xBA-vs-AVG gaps suggest BABIP luck regression is coming.
What counts as a good xBA
Higher is better — roughly .230 is poor, .250 average, .270 good, and .290 or better elite.
Also written
expected_ba · xba_value · estimated_ba_using_speedangle
Source
Statcast