The mouth spits and spews like a sprinkler. The eyes get as big as trash-can lids. The jaw extends farther than many industrial forklifts. The face turns hunter-orange, stoplight-red and then eggplant-purple. And that's just during warmups.

It's the best mug in sports. It belongs to Pittsburgh Steelers coach Bill Cowher. And the lint-brain refuses to do a damn thing with it.

Most coaches do ads all the time. Cowher doesn't do any. He isn't even on a billboard. My lord, you could do a billboard on that anvil jaw alone. He could be making millions with that face. Instead, he locks it up like a pound of plutonium.

Worse, he still lives in the same 3,000-square-foot house he moved into 13 years ago. He hasn't even added on to it. He hasn't written a book. Hasn't done Letterman. Doesn't have a restaurant, a Hummer dealership or even a Big and Tall Shop. Will do only one lousy speech a year--for a YMCA in Pittsburgh. Won't go out on the town. Who is he, Greta Garbo?

The guy has the best team in the NFL. He's had his job longer than any other coach in the league, and he's only 47. He's a Houdini who's taken his team to the playoffs nine times in his 13 years and done it with quarterbacks who should've been selling aluminum siding somewhere--guys named O'Donnell, Tomczak, Stewart and Maddox--and now a rookie, Roethlisberger.

And do you know the deep, dark reason why he won't cash in? Because he is constantly hanging around young girls, that's why.

His daughters.

Turns out Cowher has this antiquated idea of fatherhood: He thinks a dad should be devoted to his kids' lives, not vice versa.

It's worked out nicely for his three girls, all of whom have blossomed into basketball whizzes, starting with Meagan, 18, a Princeton freshman who is killing the Ivy League already. She had 28 points in a game last week, 19 two nights later and has helped turn the Tigers around.

His middle daughter, Lauren, 17, is one of the best high school players in Pittsburgh, where she plays for Fox Chapel the way Cowher coaches: red-faced, diving into the Gatorade jug, punching herself in the leg after mistakes. His youngest daughter, Lindsay, 14, who plays on middle school and AAU teams, may be the best of all.

For them Cowher acts like a witness against the mob. "I don't want my face all over town," he says, "because when I'm not working, I just want to be their dad in the stands. Nothing else."

Somewhere, his agent weeps.

And so here we are at the end of Lauren's game last Friday night. As usual Cowher is in the stands, yet not a single person has come up to him for an autograph or a photo. "They know me here only as Lauren's dad," he says, happily.

Actually, a lot of people know him as the Guy Who Tries to Keep Lauren's Mom Calm. That would be Kaye Cowher (née Young), the former North Carolina State and Women's Professional Basketball League star. Kaye gets a little, uh, enthusiastic. Bill won't even sit in the same row with her. "Otherwise, she hits me all night," he says. There may be a maniac in the Cowher family, but it's usually not Bill. Except on Sundays.

"My friends ask me, 'Do you get that face if you don't do your laundry?'" says Lauren. "But the only time we see that face is on TV. He'll be going a little crazy, and my mom will kind of cover her eyes and go, 'Oh, Bill!'"

On Saturday, when Pittsburgh hosts the New York Jets in the AFC divisional playoffs, Steelers fans will pray that Cowher won't make 65,000 at Heinz Field cover their eyes and go, "Oh, Bill!" The playoffs are to Cowher what Bugs Bunny was to Elmer Fudd. He's 7--8 in the postseason and has lost three out of four AFC Championship Games, all at home.

Not that he'll get fired anytime soon. Because the only people with more antiquated ideas than the Cowhers are the Rooneys, the family that owns the Steelers. They have this lace-doily notion that loyalty and stability mean something. In fact, when Cowher went 6--10 in 2003, the Rooneys extended his contract another two years. The press howled. Cowher repaid the Rooneys with the first 15win regular season in AFC history.

Hmmmm. The Rooneys have had two coaches in the past 36 years, and they're still winners. Anybody want to mention that to the Washington Redskins? Or Notre Dame?

And if the team ever does fire the Pittsburgh-born coach with the world's worst poker face, Cowher would still belong to a family that he loves--and vice versa.

"My dad is one of my best friends in the world," says Meagan.

She pauses.

"Plus," she adds, "we didn't get the jaw. That's a good thing."

The best mug in sports belongs to Bill Cowher. He could be making millions with it. Instead, he locks it up like a pound of plutonium.