The home team trails 2-0 in the bottom of the ninth, but two men are on, and baseball's leading home-run hitter, Dave Kingman, is at bat. Fans are screaming "Go, go!" Joe Mantegna is not overly excited.

He knows that he is at Wrigley Field, where the home team is the Chicago Cubs. He knows they have not won a championship in 34 years, a record of futility unsurpassed in modern professional sports. He knows that it is September, and that September pennant pressure is to the Cubs what kryptonite is to Superman.

Mantegna is therefore not surprised when Kingman hits into a double play, the rally ends and St. Louis wins the game.

"I've been disappointed for 31 years," says Mantegna, 31. "My father got so tired of the Cubs losing that he became a Chicago Anything fan—Black Hawks [hockey], Zephyrs [basketball], the Sting [soccer]—any team from Chicago that might win. The same thing is happening to me. If Chicago had a midget lacrosse team that won, I'd support it."

Mantegna, an actor, actually lives in Los Angeles now. Being a Cub fan, however, like being myopic, is not something one outgrows. He has a professional reason for his fidelity as well. Mantegna is the creator of a play titled Bleacher Bums which opened in Chicago in summer 1977, moved to New York a year later for a short but critically successful run and will be performed on public TV in mid-October.

Set in the Wrigley Field bleachers, where admission is still only $1.50, the play, says Mantegna, "is not a Cub play. It's a fans' play. It is a mixture of beer and heat. By the eighth inning these fans go berserk. But it is a mixture of beer, heat and frustration."

Mantegna's art imitates life at Wrigley Field. There, as in the play, fans bet on every pitch, beer vendors are known by their first names and a blind man comes to every game with a transistor radio.

The Cubs themselves are interesting if not adroit. Their player roster over the last three decades has included a 38-year-old rookie pitcher with a gold earring whose major league career victory total was zero, a substitute infielder best known for his skill on the trumpet and a double-play combination whose propensity for wild throws earned it the nickname Miksis to Smalley to Addison, the last name being that of the street behind the first base stands.

The Cubs nonetheless engender miraculous loyalty. In 24 of the last 35 dismal seasons, they drew more than 875,000 people, even though their home games are always televised and they never play at night. (Wrigley Field is the only major league stadium in the U.S. without lights).

Part of that loyalty owes to superb individual players—Andy Pafko, Hank Sauer, Billy Williams and, Mantegna's favorite, Ernie Banks. Part of it is sheer perversity. "I watched my first game here at Wrigley Field in 1916," says Joe Mantegna's Uncle Lou, 77. "They were losing then."

Joe attended Chicago's Goodman School of Drama and was with the city's Organic Theater when he thought up the idea of the play; other actors built on it. (The title came from a group of fans who organized when the Cubs became tantalizingly good in the late '60s; they wore yellow helmets and cheered in unison but when leaner years returned, they vanished.)

Mantegna, who is married to a scriptwriter, later appeared in Studs Terkel's play, Working, wearing a White Sox uniform. (It was a difficult role: The Cubs-White Sox rivalry in Chicago is fratricidal.) Joe actually is more at peace with his depression over the Cubs than many fans. When the team came close to a title in 1969 only to have it snatched away by the Mets, "I decided I wasn't going to let them break my heart anymore." Now that he is in L.A., writing and doing TV, film and commercial parts, he sometimes even goes to Dodger Stadium (always wearing a Cub jersey).

His beloved team is an also-ran again this season. And yet. "Next April," he says, his eyes alight, "when the snow is gone, the Cubs will come back. Maybe they'll win." It is not the voice of lunacy but love.