On May 20, 2015, David Letterman will air his final episode as host of The Late Show, before passing the torch to Stephen Colbert. It’s likely that many of Letterman’s classic bits and routines will retire with him, and rightly so. Stupid Pet Tricks, Will It Float?, and the nightly Top Ten List don’t seem like gags that should be associated with anybody but Letterman. The latter is practically an extension of the outgoing host’s persona, with 29 years of nightly delivery.

Ben Blatt of Slate has devoted considerable energy to researching the signature bit, performing a statistical analysis of every Top Ten List read on air—over 4,100 lists. Relying on fan websites for some of the older transcripts, Blatt crunched the lists, and came out with some interesting finds, including:

  • Regis Philbin is the most frequently mentioned celebrity. (Kathie Lee Gifford provides symmetry by coming in at number 10.)
  • Entry number one is by far the most likely to have the fewest words.
  • Dave’s writing staff has a strong propensity to use the nouns “ass” and “pants” both in the lists and on the show in general.
  • David Letterman is the person most frequently listed in David Letterman’s Top Ten Lists (Blatt isn’t counting Letterman as a celebrity).