The most prestigious clerkship is one with a U.S. Supreme Court Justice; there are only 37 of these positions available every year. However, in recent times securing a federal court of appeals clerkship with a federal judge has been a prerequisite to clerking on the Supreme Court. Therefore, the second most prestigious place to clerk is at one of the U.S. courts of appeals. Further, clerkships with certain appellate judges, such as J. Michael Luttig, who have sent many clerks on to the Supreme Court, often called "feeder judges" are especially difficult to obtain. Luttig, before his retirement, was the leading "feeder" judge on the U.S. Court of Appeals, with virtually all of his law clerks having gone on to clerk with conservative justices on the Supreme Court, a total of 40 with 33 clerking for either Justice Thomas or Justice Scalia. This reflects the increasing polarization of the court with both liberal and conservative judges hiring clerks who reflect their ideological orientation.