Mark Uyl has been watching, coaching or refereeing Michigan high school sports for three decades. The hundreds of games he has seen, especially when they are played indoors where the spectators are close and the sound is magnified, have revealed at least one “absolute truth,” he says. “That coach who is ranting and raving up and down the sideline, gesturing and emotionally reacting to calls and non- calls,” Uyl, the executive director of the Michigan High School Athletic Association, tells USA TODAY Sports, “I can tell you 100 percent of the time, that tends to inflame that school’s fan base. “The way that coaches act,” he says, “has a direct correlation for how their spectators act.”