Feb 10, 2021 - Sports

MLB attempts to de-juice its baseballs

Illustration of a baseball being juiced like an orange over a citrus juicer
Illustration: Sarah Grillo/Axios

MLB is slightly altering the construction of its baseballs in the hopes of deadening them off the bat.

Driving the news: The league sent a memo to all 30 teams outlining changes that would "center the ball within the specification range" of bounciness — a range that has always been wide enough for significant variance among balls.

Why it matters: After years of surging home run rates amid claims of a juiced ball, the notoriously tight-lipped league has finally gone public with meaningful equipment changes and the reasons behind them.

The backdrop: Five of the six highest home run rates in MLB history came in the past five seasons (the other was in 2000, at the height of the steroid era).

  • Players have questioned if juiced balls were the culprit, but MLB has repeatedly said no intentional changes were made.
  • Independent auditors have attempted to test the balls to find clues, but getting their hands on game-used equipment is easier said than done.
  • "They're very shady about things," an unnamed team employee told SI. "Everything's gotta be a secret. It's not the CIA here, right? This is baseball."

The state of play: Balls are comprised of a core made of cork and rubber; a center of four distinct layers of wound yarn; and a cover of stitched leather.

  • Changes — namely to the ball's size, weight and bounciness — can alter the way it flies off the bat.
  • Per its memo, MLB will decrease the bounciness by loosening the tension of the yarn in the center.

What to watch: There's no guarantee these changes actually de-juice the ball as intended.

  • The Korea Baseball Organization in 2018 successfully deadened its ball by similarly reducing bounciness, but also by increasing the size and weight, which increased drag and kept the ball in the park.
  • MLB's new ball, by contrast, is expected to be ~2.8 grams lighter, which could actually reduce drag and offset any change resulting from the decreased bounce.

P.S. ... In other MLB news, the league released its new health and safety protocols for the 2021 season, including mandatory contact-tracing wearables and very few exceptions to leaving the hotel while on the road.

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