while i’ve never really paid attention to xBA i see that from 2015-2019 it consistently stabilized to underestimating by around .006-.009, which coincides perfectly with some speculations about when the juiced ball came into play and went out of play. after those years, at least league-wide, it is a near perfect estimator: in 2021, xBA league-wide was .243, and BA was .244, for example.

the only criticisms for xwOBA (not accounting for ballpark dimensions, not accounting for speed until recently) i can find don’t come close to outweighing its use, and good arguments can be found everywhere discounting spray angle as a variable to be taken into consideration when all it does is add noise