INDIANAPOLIS — One family’s curse can be another family’s blessing, but for the Andretti clan they are one and the same when it comes to the Indianapolis 500.

For more than five decades the Andrettis, starting with family patriarch Mario, have had a complicated relationship with the Indianapolis Motor Speedway (IMS).

American motor racing royalty, the Andrettis have ruled over open wheel racing in the United States with a string of victories that have connected generations — father, to son, to grandson.

But for all their success at circuits around the world, Mario Andretti’s Indy 500 victory in 1969 stands alone.

That win 50 years ago this weekend was expected to be the first of many for Mario at the Brickyard.

He had already won a Daytona 500 and in 1978 would claim the Formula One drivers’ title but he would never again roll on to Victory Lane at IMS.

His son Michael, a five-times winner of the Indy 500 as a team owner, tried 16 times as a driver but never chugged from the winner’s quart of milk.

Neither has Mario’s youngest son Jeff, nephew John or grandson Marco, who will carry the family flag into Sunday’s race.

Such has been their cruel misfortune that the thinking is there could be no other explanation for the Andretti heartbreak than a curse.

Exactly what it was that so angered the racing gods, however, is uncertain.

Folklore has it that in 1970 Mario got in the middle of a feud between team owners Andy Granatelli and Clint Brawner. When Andretti sided with Granatelli, Brawner’s wife put a hex on the family promising no Andretti would win the Indianapolis 500 again.

“I never took it seriously, as a matter of fact I don’t endorse it (a curse) whatsoever,” Andretti told Reuters. “When I look at the big picture of what Indy has meant to us, what we have been able to do there, ok we were not able to control certain things that were out of our control but the fact that we led so many laps, between Michael and I especially, they knew we were there.

“Between Michael, Marco and myself we have 16 podiums,” he added. “Indy has done a lot for us so, no not a curse. I say a blessing.”

If the Andrettis are infatuated with the Indy 500, it is because the race has been a shameless flirt.

The 1981 race

Certainly the Andrettis have plenty of reasons to feel jilted with Michael and Marco both having posted runner-up results.

Mario reflects on his own bad luck with an “it is what it is” shrug until the controversial 1981 race enters the discussion.

That year, Andretti crossed second but was declared the winner when Bobby Unser was disqualified for an illegal pit stop. Five months later on an appeal Unser was fined $40,000 and reinstated as the winner.

“By the rule book I won that race,” Andretti said. “I would have paid $40,000 all day to cheat 11 cars and cross the finish line first. “

At 79 years old, Andretti, who still takes passengers for two-seater rides around the Brickyard at close to 200 mph, remains the most popular and best known racing driver in the United States.

Fifty years on, his victory still resonate with race fans.

Museums have set up displays to mark the anniversary, a commemorative bronze pin has been stamped and Andretti merchandise is flying off the shelves of specially set up Mario merchandise stores.

Marco Andretti will pay tribute to his grandfather on Sunday by driving a car with the same day-glow red livery Mario used for his memorable 1969 victory.

The only detail yet to be worked out is an Andretti win on Sunday which would be a fairytale bookend to a family dynasty.

“There is something about that place that is so special,” Andretti said. “You would hear my screams wherever you are if Marco wins, I guarantee it.

“This would be the sweetest moment. For what it means and the amount of time that we have devoted to that (the Indy 500) would be the ultimate reward.”