Offense
Route tree
The numbered set of receiver routes — flat, slant, comeback, curl, out, dig, corner, post and go.
The route tree numbers a receiver's core routes so a whole concept can be called in three digits. Even numbers break toward the sideline and odd numbers break inside.
Route depth is what connects the tree to props: a receiver living on slants and flats has a very different yardage profile to one running digs and posts.