First, "early" means pre-plan. Now, it's not technically "early" to hire graduates pre-plan, but it's a way of distinguishing when judges move and how quickly.
Second, a listing as "not early" may actually mean early. If a judge hires a clerk on August 1, but it is reported on this site on October 1, then it is recorded as "not early," even though it was an early hire. Note, however, that the converse cannot be true, which means that the "early" hiring statistics are a guaranteed minimum.
3L early 46 9.3%
3L not early 243 49.3%
Grad early 114 23.1%
Grad not early 67 13.6%
Unk early 12 2.4%
Unk not early 35 7.1%
Judges known to have hired 3Ls before Labor Day:
Fisher, Van Antwerpen Sr. (3)
King, Niemeyer, Shedd, Wilkinson, Williams (4)
Barksdale, Benavides, Smith, Southwick, Garwood Sr. (5)
Posner (7)
Ikuta, Kozinski, Reinhardt (9)
Gorsuch, Henry, Kelly, Tymkovich, Baldock Sr., Ebel Sr. (10)
Dubina, Pryor, Cox Sr. (11)
