Trying to persuade Helio Castroneves to rank his three Indianapolis 500 victories is tantamount to asking an adoring mother or father to rank their children in order of affection.

Ask him what it would be like to win a record-tying fourth — at the 100th running of the iconic race Sunday and on the 50th anniversary of Penske Racing — it is impossible for Castroneves to deny: It would mean more than any other victory in an open-wheel career spanning nearly two decades.

"It's a special number," he said. "It's something bigger."

The road to immortality began in 2001, when as a rookie he weathered a lengthy rain delay and a battle with Gil de Ferran to first get his face engraved on the Borg-Warner Trophy. He took a victory lap and then parked on the yard of bricks, climbing up the catch-fence with several crew members in a wild celebration.

He made the same climb the following year, when a crash just before Paul Tracy passed Castroneves on the 199th lap gave him the victory. There were protests and appeals hearings, and many still believe Tracy deserved to win the race, even though Castroneves had the victory officially upheld that July.

There was no such controversy seven years later.

Two months after he was acquitted of federal charges of tax evasion and conspiracy, he won the race from the pole position in dominant fashion, never allowing Dan Wheldon and Danica Patrick to make a run.

Three victories in less than a decade.

It's almost hard to fathom he's been chasing No. 4 for so long.

"The good news is we're here. We're pushing," said Castroneves, who will start outside on the third row Sunday. "We're finding every inch in the track to make sure that we can make it happen."

For all his wins, there have been just as many near-misses.

Castroneves was leading the 2003 race with about 30 laps to go when de Ferran passed him, the two of them eventually giving Team Penske another 1-2 finish. He finished third behind Dario Franchitti and Scott Dixon four years later, and was fourth in 2008, when Dixon drove to victory after a late restart.

None of those was as painful as two years ago.

After a late wreck had brought out a red flag, Ryan Hunter-Reay and Marco Andretti joined Castroneves in a high-speed game of musical chairs. Castroneves took the lead with two laps to go as Andretti began to fade, only for Hunter-Reay to overcome him on the final lap. Castroneves made one more move, coming out of the last corner, but wound up second by 0.0600 seconds — the second-closest finish in race history.

"Listen, every time we don't win, that's part of the sport, but you remember it for a long time," Castroneves said with a brave smile. "The team does not have a short memory. They always remember the success. But I remember the ones that I didn't get. They hurt more."

The fact that he could smile about a defeat, even if it was merely a facade, is one of the reasons he's been so successful. The Brazilian's effervescent personality permeates Gasoline Alley, and the perpetual optimism that he carries onto the speedway has allowed him to overcome plenty of misfortune.

"He's got this spark when he drives. You see it sometimes," said Team Penske teammate Simon Pagenaud. "He has that something special, for sure. His spirit makes him so he doesn't give up. He believes he can."

That personality may rub some the wrong way, but it's also made Castroneves plenty of fans.

"He behaves like a 22-year-old. He's such a good spirit," Pagenaud said. "It's inspiring."

Castroneves is back this weekend in Roger Penske's renowned "Yellow Submarine" car that he nearly won in two years ago, and that Rick Mears made famous in the 1980s. And if he can guide it to victory lane Sunday, he will join Mears, A.J. Foyt and Al Unser in the exclusive club of four-time winners.

That mere thought made Castroneves reminisce about his first trip to Indianapolis.

"I came here to do something, an appearance, and I came to the track but I went to the museum — that's as far as I went," he said. "I remember touching the trophy and said, 'One day, my face will be on here.'"

Three times and counting.