Why Home Runs Are on the Rise

  • By Ari Daniel
  • Posted 10.25.17
  • NOVA

Bigger swings? Faster pitches? Discover what's driving the recent surge in home runs in baseball.

Running Time: 03:15


Why Home Runs Are On The Rise

Published October 25, 2017

Onscreen: Why are home runs up? Since 2014, home runs have increased in Major League Baseball by 47%.

Some wonder if it's linked to performance enhancing drugs, as in the past. But now drugs are more tightly monitored. Plus, steroids tend to produce a big surge by a few players. And now MANY players are hitting more home runs.

Physics may help find the real reason.

We asked a pro and a physicist who loves and studies baseball.

Matt Antonelli: You have just under four tenths of a second from the time the ball's released till it hits the catcher's mitt. When you're physically in the box and the pitch is coming, you think about nothing but the ball.

Alan Nathan: From a physics perspective, you're trying to figure out how to hit the ball as far as possible. The primary thing is how fast that bat is moving when the ball and the bat make contact.

Onscreen: Every extra 1mph of bat speed means an extra 1.2 mph of ball speed, giving a fly ball an extra 6 feet of distance. Then there's launch angle.

Antonelli: That's the angle that the ball is going to leave the bat. And optimally, you're looking to create one between 25 and 35 degrees.

Onscreen: The launch angle is based on where the bat contacts the ball. A hair above center gets you a ground ball. A hair below center gets you a fly ball. We're talking a precision of millimeters. The ball should also hit the bat's "sweet spot."

Nathan: This is the place along the length of the bat that is best at transferring energy to the ball. It's typically maybe 5 or 6 inches in from the end of the bat.

Onscreen: Hit the ball elsewhere, and the bat vibrates. That's lost energy.

So why the upward trend in home runs? No one knows for sure.

Some think it's the baseballs, not the players, that are "juiced." That they're a bit smaller, with lower seams, creating less drag.

There's another possibility.

Nathan: Batters are simply trying to hit more home runs.

Onscreen: In other words, the whole strategy of the game may be shifting.

Antonelli: When I first started coming up in Major League Baseball, we were taught to hit the top part of the ball. Try to hit a hard ground ball. And if you get lucky, maybe you'll hit a little bit lower and maybe you'll get a home run. Now, if you fast forward, players now are trying to actually hit just below the center of the ball to try to create more home runs.

Onscreen: Fly balls and strikeouts are up too — more evidence that hitting philosophy has changed. No matter the reason, some things likely won't ever change.

Antonelli: I've played at stadiums where there's 50,000 people screaming. And when you get in the box and the pitcher, he's about to deliver, I don't remember hearing anything. It just goes completely silent. I think you're so locked in. So when I've hit, I've never heard the crack of the bat, I've never heard anything, none of that matters. And then once you finally start to run, then all of a sudden it comes back.



Digital Producer
Ari Daniel
Editorial Review
Julia Cort & David Condon
Production Assistance
Will Sullivan
Bella Solanot
Theresa Machemer
and Ivy Liu
Special Thanks
Jeff Cunningham & Brittany Flynn
© WGBH Educational Foundation 2017


Ari Daniel
Additional Visuals
Washington State University Sports Science Laboratory
Louis J. Spirito | THIRTY81Project.com
West Ohio Sports Net
Noun Project: Magicon
­APM & freesound.org


(main image: baseball)
© WGBH Educational Foundation 2017

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