It is 14 October 2003. Steve Bartman, a 26-year-old global human resources company worker from Chicago, Illinois, is sitting in Aisle 4, Row 8, Seat 11 at Wrigley Field. His team, the Cubs, have not reached the World Series since 1945. This seems set to change as, 3-2 up in a best of seven series, they take a 3-0 lead into the eighth inning against the Florida Marlins, whose second baseman Luis Castillo is at bat. He sends a foul ball high into the sky, the Cubs outfielder Moisés Alou hares round to catch it, if he makes the play then the Cubs will be four outs from the World Series. He reaches out but Bartman beats him to it and deflects the ball away from Alou. This is how Thom Brennaman on Fox calls the play: "Again in the air, down the left field line. Alou reaching into the stands and couldn't get it and is livid with a fan."

It is a pivotal moment. The Cubs go to pieces. Instead of closing the game out they produce a comedy of errors and slide to an 8-3 defeat with six of the runs being unearned. Bartman, pelted with drinks and other debris, is given a police escort from the stadium. Not exactly how this alumnus of Notre Dame was imagining his evening might end.

Things quickly deteriorate. Bartman is outed on a Major League Baseball message board. The mob descends on him. Six police cars are on call outside his house. Rod Blagojevich, the since disgraced governor of Illinois, helpfully suggests that Bartman join a witness protection programme. His counterpart in Florida, Jeb Bush, offers Bartman asylum. "Stuff happens," says the then-President's brother.

Bartman, as is customary, issues an apology: "There are few words to describe how awful I feel and what I have experienced within these last 24 hours … I am so truly sorry from the bottom of this Cubs fan's broken heart. I ask that Cub fans everywhere redirect the negative energy that has been vented towards my family, my friends, and myself into the usual positive support for our beloved team on their way to being National League champs."

To do this they must win the decider. The Cubs manager, Dusty Baker, says: "We've got to win for that kid. For us, it's just a ball game. For him, it's the rest of his life." His brother Martin says: "He's really hurting right now. I love him so much I'd give up a piece of my anatomy for him."

The Cubs take a 5-3 lead. Salvation may be at hand. They lose 9-5. The Marlins go on to win the World Series.

(The Cubs have not won a play-off game since "the Bartman incident", having been swept by the Arizona Diamondbacks in 2007 and the LA Dodgers in 2008. Last week they filed for bankruptcy protection.)

Bartman, pilloried at every turn and advised by the police not to go into work, goes into hiding. To this day he has not spoken about the incident that carries his name.

It was his misfortune to have added a further slice of ill luck to a club burdened by a cake full of the stuff. Eric Neel summed up the despair felt by the fans. "We're just like Icarus today, baby, nothing but a close-but-no-cigar mess of wax and bones. The Cubs didn't lose, the Cubs are losing itself. We define the concept so that winning has meaning. We are the yardstick, the baseline. You get me?"

As ever the anonymous reactions on the internet are ugly and chilling examples of mob rule. "Death to Steve Bartman" message boards are set up. There are pictures of Bartman in Saddam Hussein's bunker and mug shots of Bartman as the lead suspect in the Washington DC sniper shootings. He is vilified.

Jay Mariotti, a sports columnist for the Chicago Sun-Times, writes: "A fan in that situation should try his best to get out of the way, even if he isn't of the mind to see Alou approaching, as Bartman claims. Still, he's also a human being who was reacting in a tense, unusual moment. And the resulting verbal abuse and trash-hurling, followed by the Neanderthal threats and creepy reaction on the internet, hasn't reflected well on Chicago's sports culture. As it is, everyone thinks the prototypical local fans are those mopes from the Superfans skits on Saturday Night Live."

Meanwhile, the ball, which, perhaps inevitably, was ambulance-chased by a Chicago lawyer, is sold at an auction in December 2003 and purchased by Grant DePorter for $113,824.16 (£70,091) on behalf of Harry Caray's Restaurant Group. On 26 February 2004 it is publicly detonated by the special effects expert Michael Lantieri, with the remains of the ball being used by the restaurant in a pasta sauce.

Boringly, health and safety considerations come in to play, preventing any part of the ball adding some much needed chew to the bolognese. Instead, the steam of the ball is captured, distilled, and added to the final concoction. A style of cooking we haven't seen enough of during this year's Masterchef: The Professionals.

On the small screen, an episode of Law and Order features a character called "the foul ball guy" who is murdered in a bar. "It was gratuitous," is the verdict of Bartman's lawyer, Frank Murtha.

And now Alex Gibney, who directed Enron: The Smartest Guys in the Room, is making a documentary about the poor man. "It's not the search for Bartman," he has said. "It is about how does one become a scapegoat?" Which may not completely reassure the fan who reached out too far.