Skip to main content

The science behind Hunter Pence’s powerful home run swing

Folks in Kansas City might not want to read any further, but they’ve certainly already witnessed the powerful science behind the swing of San Francisco's Hunter Pence.

The Giants’ outfielder’s first-inning home run helped establish a scoring presence in the first game of the World Series on Tuesday. Pence, though, has used swing analytics to help hone that swing into one of the fastest in professional baseball.

Trevor Stocking, Zepp Labs’ baseball product manager, the California-based company that recently released an updated swing analytics app and sensor as revealed by Edge, says working with Pence on the new product gave Stocking insight into the special swing.

2014 World Series: Royals vs. Giants position-by-position breakdown

​Throughout practice sessions, Stocking found Pence swings with an average bat speed at impact of 106 miles per hour, well above the average needed for success. With a hand speed of 41 miles per hour, Pence is able to spend just .108 seconds from the start of his swing to the point of contact, the fastest of any of the pros Zepp worked with.

Pence says in a Zepp hitting video that he’s always known about the saying “short to and long through” in relation to swinging. “Instead of just a saying you have to figure out, you can actually see if you are figuring it out,” he says about Zepp's swing analytics. “Now you have the answer.”

And while Pence admits his swing looks “spazzy,” it works for him. “It doesn’t look fluid to you, but it is fluid to me,” he says. “It is the rhythm of my body.”

Stocking says embracing that personal fluidity allows Pence to increase the speed of his swing in a controlled motion and get the barrel of his bat into that eight to 12 inches in front of the plate, making contact with the ball in front of his stride foot.

On Tuesday, the home run ball came to the plate at 94 mph, but left Pence’s bat at 108 mph with a 21-degree angle.


“Your bat speed, hand speed and swing time are not as good when you don’t have fluidity,” Stocking says. “Hunter Pence has a very unique rhythm, timing and fluidity.”

Using the Zepp app, users can watch video of the Pence swing, telling the story with just his bat. “When you look at his bat, it is just like all these other pros, but it is better,” Stocking says.

More swing data from Stocking shows that Pence, on average, swings with an attack angle of 14 degrees, an angle that commonly falls in the line drive category. And while 14 degrees may not send a ball towering high out of the stadium, with a bat speed as fast as Pence, he quickly makes up for any height constraints. For every mph increase in bat speed, Stocking says, players add an extra five to seven feet of distance. When you add in the fact that Pence swings a 32-ounce “tree trunk” of a bat, what would be a line drive for some, gives Pence enough pop to see the ball leave the field of play, whether in AT&T Park or even, to the dismay of those in Kansas City, in Kauffman Stadium.

Tim Newcomb covers stadiums, design and gear for Sports Illustrated. Follow him on Twitter at @tdnewcomb.