Giancarlo Stanton had half an hour, and he was about to remake himself as a hitter.
It was June 19 in Miami, and the Marlins were preparing to host the National League East-leading Nationals. Beneath a closed Marlins Park roof, Stanton began his experiment. He had watched endless video clips, and he was ready to test what he'd envisioned: He closed his stance.
"I just said I was going to try it. Honestly, I had about 30 minutes of work, maybe 45 minutes, before the game," Stanton told MLB.com Sunday, when he crushed his Major League-leading 45th home run against the Mets at Citi Field. "And then 10 minutes before the game, I was like, 'This feels more comfortable.'"
When Stanton stepped into the batter's box in the first inning, he positioned himself in a way he hadn't all season. His front foot was closed off -- nearer to the inside edge of the box than his back foot, angling his 6-foot-6 frame acutely toward the imaginary line connecting the pitcher to home plate, rather than parallel to it. For his first 66 games in 2017, Stanton had been predominantly square to the pitcher.
The first at-bat, Stanton grounded into a double play. But then he singled in the third inning, 113.9 mph off the bat according to Statcast™. Stanton homered in the seventh, a 105.9-mph, 398-foot shot to the opposite field. Over the following games, the new stance didn't just stick, it exaggerated. By July, he was more closed than he'd ever been before. Now, well into the second half of the season, Stanton is one of the most closed off hitters in baseball.
"My best striking position is closed," Stanton said. "It's not smart to try to completely change something in the middle of the season. But if you are 100 percent committed to it ... well, you've got to be. You've got to trust what you're trying to do. If you change something, you want results right away, otherwise you try to go back. But I trusted it completely and let it ride."

Stanton's closing of his batting stance has correlated with his massive power surge. On June 18, he had 17 home runs in 282 plate appearances; since June 19, he has 28 in 236. Stanton has homered in 11 of his past 16 games, including a run of six straight last week. He's made himself into a candidate to be the National League's Most Valuable Player.
It's easy to see why Stanton might benefit from a closed stance. His swing involves a high degree of rotation -- with his hips and upper body, which carry the bat along with them. Because of Stanton's sheer size and strength, the torque he generates is unique, and it can produce some of the most dramatic home runs in the game. But through his career, he has had the tendency to rotate too early.
Stanton has generally used either a square or open stance type, vacillating between the two -- his front foot either straight to the pitcher or barely ajar toward third base. Last season, he used mainly the slightly open style that has become ubiquitous in the modern game. When Stanton hits from those positions, his front side can come open before the pitch arrives, leaving him exploitable.
The closed stance is a natural counter. When Stanton is already turned inward to start, his rotation drives him into the pitch, instead of causing him to fade away from it. His movements with body and bat upon the pitcher's delivery -- his swing -- are by and large the same. It's the starting point, the stance specifically, that's shifted. But that can make a huge difference in how a hitter like Stanton gets to the ball.

Over the years, Stanton has frequently rearranged his foot position, often cycling through multiple stances within a season. Sift through old highlights and you can find them -- beginning with his rookie season, when he was wide open and crouched low ("It's like the complete reverse," he said.). None were closed off to this degree.
"Never. Never in my history of playing baseball," Stanton said. "So you don't know what you're going to get. But if you have some good key points, you should be all right."
With his adjusted stance, Stanton has been driving the ball in the air more often. His rate of fly balls and line drives, per Statcast™, has risen from 41.5 percent prior to June 19 to 50.3 percent since. Stanton's average exit velocity on those balls has increased from 97.6 mph to 100.8 mph, the highest in the Majors over that time.
"[His stance] gets him in the position he wants to be in. It looks like it's keeping him on the ball more, and he seems like he's seeing it better," said Christian Yelich, who's played alongside Stanton as long as any current Marlin -- since 2013, when he was 21 and Stanton 23. "Some guys have different problems than others. You go about fixing them or covering them in different ways. It's all about feel. That's what works for him, that feel."
Major League batting stances have tended toward sameness in this era. The slightly open stance is king, and few hitters hit from a significantly closed starting point. But at a level of the game where emulation is fundamental, success begetting imitators, Stanton found his prototypes: Nolan Arenado, Matt Kemp, Adrian Beltre, prominent hitters who do close off. He recognized past greats, too: Hall of Famer Andre Dawson works as a special assistant to the Marlins, and he hit with a closed stance in his playing career. Stanton didn't copy the technical aspects of their batting stances, but their accomplishments gave him precedent to actually make the change himself.
"I just know the guys with success," Stanton said. "Arenado and Kemp, those guys, you know you can have a high average with it. So that kind of gave me the green light to try it.
"I knew it could work. Not very many people did it. But I know people like Hawk and them did it in the old days -- and it worked for them, too."
It was a matter of taking the plunge and joining the outliers. Stanton might not stick with his closed stance forever, but the ends have been justifying the means for two months now. He's on pace to easily become the National League's first 50-homer hitter this decade -- a pace he was not on in mid-June -- and there have been whispers of 60.
"The thing about Giancarlo, he's a little bit like Big Mac when he was rolling along," manager Don Mattingly said, referencing Mark McGwire. "You felt like you could get him out if you made pitches. He strikes out enough, he swings and misses enough, that you think, 'Oh, if we can get the ball here or there, we can get this guy.' And then the danger comes."