Jerry Seinfeld Returns to TV Stand-Up

Explains ratings system to David Letterman.

Jerry Seinfeld made a rare return to TV stand-up comedy on the Late Show With David Letterman Tuesday night.

The comic explained the new rating system: "The only ratings anyone cares about is sucks and great. They're the same."

He also joked about 5-hour energy drinks, and being embarrassed performing with Paul McCartney in front of President Barack Obama at the White House.