What can Vice Presidential candidate Paul Ryan expect Thursday night? Biden can be quick on his feet, unpredictable. One of his best debate moments was so out-of-the-box it became a classic because it was the opposite of the kind of thing Biden is known for—not being able to shut up long past when he should have.

During a Democratic debate in the 2008 primaries moderated by Brian Williams, the NBC newsman asked Biden if he could put a lid on the gaffes and show discipline “on the world stage.” Biden said, “Yes.” And left it there. Admittedly, there are gaffes and there is kicking ass.