Predicting an Indianapolis 500 winner is hard. Just ask the Andretti family

One compelling aspect of the Indianapolis 500 is that the race is so difficult to win because so much can go wrong, no matter how fast the car.

Parnelli Jones was leading when a $6 ball bearing in his gearbox failed in 1967. A last-lap crash ruined J.R. Hildebrand’s sure win in 2011. Others have seen victory vanish with blown engines, botched pit stops and fuel strategies that backfired. The great Mario Andretti won the 500 only once in 29 attempts.

This year’s race Sunday will be the 50th anniversary of that Andretti victory in 1969 and, except for that win, the Andretti family is known for Indy futility. Mario’s son Michael never won it in 16 attempts and Michael’s son Marco has failed in 13 tries.

Michael Andretti now owns Andretti Autosport, a powerhouse team in the NTT IndyCar Series that has won the Indy 500 five times but with other drivers.

Indy’s toughness — there have been eight different winners in the last eight years — is what makes another golden anniversary this year so notable. Roger Penske first entered a car in the 500 the same year Andretti won.

Team Penske’s racers would go on to win the 500 a record 17 times, including last year with Australian driver Will Power. No other team owner has half that many 500 wins.

Power and his teammates — Simon Pagenaud, Josef Newgarden and Helio Castroneves — are poised to give Penske an 18th win in the 103rd running of the race Sunday in front of more than 250,000 spectators.

Pagenaud won the pole position last weekend with a four-lap average speed of 229.992 mph around the 2.5-mile, rectangular Indianapolis Motor Speedway. Power qualified sixth and Newgarden was eighth.

But Pagenaud reminded everyone of the gremlins that lurk at the Brickyard. “We have the best car,” he told reporters, but added “at the end of the day there is a lot that can happen. It’s a long race.”

Castroneves starts 12th in his quest to become only the fourth driver to win the 500 four times. The others are A.J. Foyt, Al Unser and Rick Mears.

“Looking forward to continuing the search for No. 4,” Castroneves recently told reporters. “Hopefully, it will be this year.”

While winning the 500 is often about avoiding bad luck, speed obviously still comes first, as Fernando Alonso can attest.

The two-time Formula One champion was trying for the second time to win the 500 and thus complete the sport’s unofficial “Triple Crown”: The Monaco Grand Prix, the 24 Hours of Le Mans endurance race and the Indianapolis 500.

But Alonso’s car, prepared by the McLaren Racing team, wasn’t up to the task and the Spaniard was bumped from the 33-car field last weekend when his speed was a fraction too slow.

“I will be enjoying [the race] from the TV, unfortunately,” Alonso said.

Marco Andretti, who starts 10th, is honoring his grandfather Mario with a car that carries the same orange-red paint scheme that Mario had 50 years ago.

Marco Andretti will drive a car with the same color scheme as the car his grandfather Mario Andretti drove to his only Indianapolis 500 victory 50 years ago.

(Michael Conroy / Associated Press)

The livery on another car is part of the California presence at the Indy 500 this year.

Hildebrand, a Northern California native who now lives in Colorado, is driving the No. 48 car in honor of Dan Gurney, the legendary Southern California driver, car builder and team owner who died last year. A No. 48 Gurney car won the 500 in 1975 with Bobby Unser at the wheel.

“Dan was one of my racing heroes,” said Hildebrand, who starts 21st for the Dreyer & Reinbold Racing team.

Another Californian, Alexander Rossi of Nevada City, won the Indy 500 as a rookie in 2016 and has been strong this season, winning the Acura Grand Prix of Long Beach last month for Andretti Autosport. He starts ninth Sunday.

Charlie Kimball, who starts 20th, is from Camarillo. Kyle Kaiser, the 23-year-old who bumped Alonso from the last starting spot, is from Santa Clara.

And 19-year-old rookie Colton Herta of Valencia has taken the IndyCar series by storm this season and has been fast at Indianapolis this month as well.

Herta, son of former Indy 500 racer Bryan Herta, became the youngest winner in IndyCar history earlier this year with a victory in Austin, Texas, and he starts fifth in Sunday’s race driving for the Harding Steinbrenner Racing team.

The drivers have their final practice Friday. On Sunday, retired NASCAR star Dale Earnhardt Jr. will drive the pace car for the race, which starts at 9 a.m. PDT and will be televised on NBC.

james.peltz@latimes.com

Twitter: @PeltzLATimes