Duel (8-9:30 p.m., 6ABC) - No slaps with a glove, pistols at 10 paces or psychotic truckers in this Duel. It's a six-episode game show in which 20 players compete one-on-one with one another in a series of trivia challenges. When four are left standing, a final showdown will determine the winner of the jackpot, which could be $1.5 million or more. The host is Mike Greenberg of radio's Mike and Mike in the Morning.