It is safe to assume that only one current big leaguer spent any time working at a McDonald's within the past four years. David Peralta is now the everyday leftfielder for the Arizona Diamondbacks, but back in the spring of 2011, he wasn’t much of anything as far as baseball went—just a failed minor league pitcher who hadn’t been a member of any organization for two full seasons. The Rio Grande Valley Whitewings of the North American League—an independent league that was founded in '11 and would fold in '12—had agreed to give Peralta a shot, but one problem was that he couldn’t afford to make the 1,400 mile drive from Stuart, Fla. to Harlingen, Texas, where the team was based. Peralta, who was 23 years old, slung fries to pay for fuel.

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There were more significant obstacles standing between Peralta and his major league dreams. One was that most independent ball players are such for a reason. Another was that while it is not uncommon for big-armed position players to turn themselves into pitchers—current major league relievers Sean Doolittle, Kenley Jansen, Jason Motte and Alexi Ogando are among the many who have done it—the opposite transformation, once undertaken by Babe Ruth and Stan Musial, has proven much rarer, especially recently. Even a good-hitting pitcher like Micah Owings, a former Diamondbacks starter, ultimately couldn’t manage it. Still, Peralta made it to Harlingen, and he was undaunted.

Now 27, Peralta isn’t just a major league regular, but also a productive one: He is batting .274 with nine home runs, 43 RBIs and an .845 OPS that ranks him 14th in the National League, just behind Troy Tulowitzki. Here are six central principles that propelled him on his remarkable, and altogether unlikely, journey.

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1. Know when to say when

Peralta grew up in Venezuela as both a pitcher and a hitter, but when the Cardinals signed him as a 17-year-old in 2005, they convinced him that his future was on the mound, as he was a southpaw whose fastball sat in the low 90s and could reach 94. “They told me, outfielder, lefty, you can find those types of players,” he recalls. “Lefty, with your arms, you can make it really easy to the big leagues, because there’s not too many lefty throwers in the big leagues. I was like, okay. I just want to play baseball.”

As of 2009, though, Peralta had an ERA of 5.69 through 18 career appearances, none of them above rookie ball. Even worse was that he had already endured a pair of surgeries on his pitching shoulder. By the time the Cardinals released him, in May of that year, Peralta had already decided that even though he was 21 years old and had never made a professional plate appearance, his baseball destiny was in the outfield.

2. Seek out mentors

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One day, not long before St. Louis cut him, Peralta found himself in the club’s spring training batting cage in Jupiter, Fla., next to one of the few players who had successfully made the transition he was about to attempt: Rick Ankiel. He had finished second in the NL Rookie of the Year balloting in 2000 as a 20-year-old starting pitcher, but after his control completely deserted him, Ankiel eventually transformed himself into a power-hitting outfielder. “I asked him, ‘Hey, what do you think?’” Peralta recalls. “’What should I do? Can you see me swing and everything, what do you think?’ He just said, ‘Hey, just believe in yourself. If this is what you want, just do it.’ I was like, this is the best advice I can get.”

3. Transform your body

As a pitcher, the 6’1” Peralta was a relatively burly 225 pounds, but he knew that to be a successful everyday player, he would have to add muscle and lose fat. So he went home to Venezuela where, for most of the next two years, he worked out twice a day, baseball in the morning and strength and fitness training in the afternoon. He also changed his diet. “For breakfast I was eating egg whites with tuna,” he says. “Lunch was salad with chicken breast. For snacks, I was eating a lot of pineapple. Pineapple is a natural fat burner.” He emerged a lithe, outfield-ready 215 pounds.

4. Play anywhere you can

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While Peralta’s body was ready to hit, no organization believed that he could do it with any consistency. He was forced to attend open tryouts for independent league clubs, finally latching on—after his pitstop at McDonald’s—with the Whitewings in 2011. He spent his first four months as a pro hitter sleeping on an air mattress, and over the next 2 1/2 years—during which he also played for the indy league Wichita Wingnuts and Amarillo Sox—he endured bus rides of up to 22 hours, earning as little as $500 a month. “It was kind of hard, but I was like, if this is what I want, I have to do it,” he says. In 225 games in independent ball, Peralta batted .359 with 28 home runs and 189 RBIs, but he played alongside just one other hitter who had ever had a major league at-bat: John Rodriguez, who spent parts of two seasons with the Cardinals in the mid-2000s. The odds remained stacked against him.

5. Be your own publicist

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​Peralta had more motivation than most Latin ballplayers to learn English: While he was rehabbing in Florida from his second shoulder surgery in 2008, he took an interest in an American woman named Jordan. “I thought, this girl, if I don’t speak too much with her, I’m going to lose her,” he says. He was driven to perfect his second language when he realized that if any major league club was going to notice him, he would have to be his own advocate. In '12, he met Chris Carminucci, the Diamondbacks’ coordinator of independent league scouting, and thereafter he called or texted Carminucci almost every day; Carminucci’s was the only scout’s number he had. “I was telling him, ‘I’ll pay for everything, just let me show the D-Backs what I got, what I can do.” Finally, on July 1, 2013, Carminucci told him that Arizona had signed him. Two days later, Peralta played his first game for Class A Visalia. As for Jordan? She had long before become his wife.

6. Never stop learning

Peralta would play in just 104 minor-league games in Arizona’s system before making his major league debut last June 1. Last year, he led NL rookies who amassed at least 300 plate appearances in batting average (.286), slugging percentage (.450), OPS (.770) and triples (nine). This season, he has taken most of his at-bats as either the Diamondbacks’ No. 2 or cleanup hitter, meaning that he has generally hit directly before or after the one teammate whose OPS is better than his: MVP candidate Paul Goldschmidt.

“We talk a lot, because I’m still learning,” Peralta says of Goldschmidt, who is currently the NL’s leader in batting average (.341) and tied for first in RBIs (72). “We have hitters’ meetings before every game, and he’s always like, hey, this guy, he does this, he’s going to throw you this. He knows all this stuff. He’s amazing.” But as Peralta's journey shows, Goldschmidt is not the only extraordinary player in Arizona.