The current chief judges of the thirteen federal circuits have several commonalities in their backgrounds, with a particular confluence at the number four:
4/13
Reagan nominees*
Bush I nominees*
Clinton nominees*
Women
Federal district court judges
Federal judges (other), e.g., magistrate
State court judges
Graduates of same institution, for both college and law school
-5/13, if include masters and law school
3/13
Assistant U.S. attorneys
State/local government attorneys
Private practice attorneys for 15+ years
Federal appellate court clerks
2/13
Federal district court clerks
LL.M.s (earned as judges)
Nominees that replaced judges elevated to the Supreme Court
*Nominees=nominees to federal appellate bench
Source, Federal Judicial Center biographies: Sandra Lea Lynch-1st, Dennis G. Jacobs-2d, Theodore Alexander McKee-3d, William Byrd Traxler, Jr.-4th, Edith Hollan Jones-5th, Alice Moore Batchelder-6th, Frank Hoover Easterbrook-7th, William Jay Riley-8th, Alex Kozinski-9th, Mary Beck Briscoe-10th, Joel Fredrick Dubina-11th, David Bryan Sentelle-DC, Randall Ray Rader-Federal.