By the time they turn 50, most people’s dreams of becoming a rich and famous athlete have long since been dead and buried – unless your game is golf, when a whole new world of opportunity presents itself.

As soon as you hit the half-century mark, you become eligible to play senior-league ball, otherwise known as the PGA Champions Tour. Age is the most existential qualifier; the other is you have to be good.

Mike Finster jumped through the more important of the two hoops a week ago Wednesday when he blew out 50 candles. As for the quality of his game, it’s something he has built for 38 years now, or ever since his father introduced him to the game as a lad growing up in the Tampa-St. Petersburg area of Florida.

It got so good for Finster over the decades that on May 28, he fired a 69 in a single-day U.S. Senior Open qualifier at Vinoy Golf Club in St. Pete. Now you can find him in the tournament that gets underway Thursday at Del Paso Country Club.

On Tuesday, Finster took a solo practice spin across Del Paso’s 18 holes and fairways bordered by a deep-cut rough that played mean early in the week, with some of the world’s finest aging golf stars.

All along the way, a gallery of five shaded Finster every bit as well as the valley oak that beautified Arden-Arcade’s loveliest grounds. Finster’s rooting section was four of his five children and his wife, Marybeth. They joined him for this working vacation in the river paradise halfway between San Francisco and Lake Tahoe.

“It is really going to be a memory my whole family is going to share for many years to come,” Finster said while leaving the course. “I was joking with my kids: ‘We go to all of (your) swim meets. You guys are coming to one of my golf tournaments.’”

On Monday, Finster practiced with Tom Lehman, winner of the 1996 British Open, and David Frost, champion of 10 other PGA events. Finster comes to Sacramento with a résumé highlighted, he said, by a third-place finish with Tom Pernice Jr. in the 2010 Outback Steakhouse Pro-Am at TPC Tampa Bay.

In real life, Finster works as a territorial manager for GAF, the largest roofing manufacturer in North America with annual sales of $3 billion. He still lives in St. Petersburg, and he has arranged with his employer to take off one of every 10 working days to refine his golf game.

That’s all Finster needed to qualify for the top tournament sanctioned by the United States Golf Association for 50-uppers.

“Is this the American dream or what?” Finster said of his participation in the senior national championship.

A high school star of yesteryear on the gulf coast of Florida, Finster attended Northwestern on a full golf scholarship. He saw his move north as a reversal of the sport’s normal geographical flow.

“Who goes from Florida to the Midwest to play golf?” he asked.

Finster departed Evanston, Ill., with degrees in political science and communication studies and a third-place finish in the Big Ten championship.

Back in Florida, “I was aspiring to be a pro,” Finster said. So his folks sent him to South Africa a couple times to play on the very politically incorrect Sunshine Tour in South Africa during the bad old days of apartheid.

“I look back, and not making a political statement, but it probably wasn’t the ideal thing (to do),” Finster said.

From the greens of South Africa, Finster observed from afar as the South African government released Nelson Mandela, who later became the country’s first black president.

Around 1991, Finster again returned to Tampa Bay, where he met Woody Austin, who would later become a successful touring pro. Austin topped $1 million in earnings seven times and, in 2007, finished 15th on the tour with $2.9 million and a noteworthy second-place finish in the PGA Championship.

But when Finster met him, Austin worked as a bartender to make ends meet. In between mixing martinis, Austin, who also is ticketed into the Del Paso event, introduced Finster to a couple of money men from Japan who had sponsored him in competition there.

A few years of flying back and forth from Florida to Japan and Finster settled back home in St. Petersburg, content to golf as an amateur while he made roofing deals and raised a family.

It was his wife who prodded him into trying out for the U.S. Senior Open.

Marybeth Finster told her man: “Get off the couch. Get in the game.”

Financially, Finster is doing just fine with GAF and has no plans to quit that gig to take up golf full time, although friends tell him he’s got enough game to give it a crack.

One look at him on the course with his wife and kids admiring and encouraging him and it’s clear he’s got it made no matter what happens at Del Paso.

Still, there he is at 50, playing with the superstars of his generation, such as Tom Watson, Bernhard Langer and Mark O’Meara.

But like Bogey in “Casablanca,” Finster didn’t come to Sacramento for the waters.

“Cinderella plans to have shoes on at that ball Sunday here at Del Paso,” he said.