Age-adj
Age-relative-to-level adjustment — credit for being young for the league.
What Age-adj means
A 20-year-old holding his own in Double-A is a far better prospect than a 25-year-old doing the same. This is the bonus (or penalty) our board applies for that gap.
Also written
age_adjustment · age_relative_to_level · age_bonus
Source
bsbl.io