If someone told you that one of the UC Davis Spirit Squad members is 20 years older than the others, sure, you could probably pick him out. The gray in the close-cropped hair; the deep laugh lines around the eyes. But otherwise, the fact that Mitch Chan is 38 years old isn't readily apparent. A talented gymnast and swimmer, Chan can "throw girls" -- the squad's term for its partner-tossing stunts -- with the best of them. Returning to school after 10 years of work as an electrical engineer in Silicon Valley, Chan is completing a master's degree in business administration and just beginning the Ph.D. program in computer science. He admits to only reluctantly telling his M.B.A. colleagues about his off-hours pursuit: "Some people might perceive it as being immature, not being focused or career-oriented," he says, but, he also confesses, "I like showing off and playing in front of a crowd." Chan and the other 13 members of the stunt squad will be performing at all home football games, the closer out-of-town games and many home basketball games this year.