He's done that more than a few times. Two years ago, he won in Atlanta(?) throwing an AI playing fourth arrow or so. There was a short bit on a pair of matches between him and Robert Smith where Smith talked about Duke playing the big hook while Smith was playing pretty straight. There was a show from '93 or '94 when Smith was an amateur as well, and in a lot of the shows from the early '90s, Duke played the big hook.
SH