When he was 9, Kevin Martin spent countless quarters racking up points on the pinball machines at the bowling alley while his mother bowled her weekly league games. More recently, Martin, the 37-year-old founder of Pair Networks, a Pittsburgh-based Web hosting company, began racking up one of the largest collections of pinball machines in the world. "As a kid, pinball got me the most value for my quarters," says Martin. "Then, in college, it was a lot more fun than going to class."

Martin began seriously collecting the machines in the late 1990s and later founded the Professional & Amateur Pinball Association. Once a year, he makes his private collection available to the public for the organization's annual World Pinball Championships, held near Pittsburgh.

Pinball machines currently owned: 460

First purchase: Dodge City, a Wild West–themed game made in 1965. Martin paid $450 for it.

Average price of a machine: About $2,000

His most valuable machine: Cactus Canyon. One recently sold for more than $12,000.

Pinball makers: There's only one left, Stern Pinball of Melrose Park, Illinois. Martin worked there as a programmer before founding his company.

Pinball technicians: Martin employs two full time. "It's pretty hard to find a pinball tech these days; most have moved on to something else careerwise," he says.

Most popular pinball machine ever made: The Addams Family, made in 1992. More than 20,000 have been sold. "It's well balanced and entertaining," says Martin.

Game over: In 2004, Martin lost 232 machines to a flood. "It was numbing," he says. "Of course, they weren't insured."

Pinball central: Martin stores his games in a 40,000- square-foot warehouse near his home.

Tournament participants last year: 312 players. The event drew about 200 spectators, including many from Sweden, where, unlike in the U.S., pinball is still popular. "Pinball is huge in Sweden," says Martin. "I don't know why."

Top prize: $10,000

Reigning pinball champ: Keith Elwin of Carlsbad, California

Controversial pinball moves: The "death save" and the "bangback," which involve bumping the machine to save a ball that is on its way down the drain. Martin bans these techniques in his tournament.