Jun 24, 2022 - Sports

MLB standardizes ball "muddying" process

MLB Opening Day baseballs.

Photo: Fred Vulch/Sports Illustrated via Getty Images

MLB's baseballs have been rubbed with a special mud from the Delaware River for decades to improve their grip. Now, the procedure for doing so will become universal.

Driving the news: The league sent a memo to all 30 teams this week detailing how balls must be prepared in an attempt to improve consistency. A minimum of 13 dozen are readied for each MLB game.

The new process: Mud must be applied to each ball on the day it will be used for a minimum of 30 seconds, with the same mud-to-water ratio, to ensure it's worked thoroughly into the hand-stitched leather.

  • Balls must also be stored in a humidor for a minimum of 14 days before use and must remain there until roughly 30 minutes before first pitch, removed only for mud application.
  • Posters depicting what a properly mudded ball should — and shouldn't — look like already hang in every clubhouse.

State of play: The baseball has been a talking point all season, as has become the norm. Players have complained about slickness differing from ballpark to ballpark, and MLB says clubhouse video confirmed that teams were applying their mud differently.

The backdrop: Baseballs have always come out of the package too glossy to be thrown reliably, so pitchers have long sought ways to improve their grip — shoe polish, dirt, tobacco juice, any substance they could find.

  • In the 1930s, a coach for the Philadelphia A's found some mud near his home in New Jersey, rubbed a small dab on the ball and found it had the perfect, pudding-like consistency to improve grip.
  • By the 1950s, every team was using this "Magic Mud" and one family, the Bintliffs, have been harvesting it ever since from the banks of a secret stretch of a Delaware River tributary.

The last word: Jim Bintliff, 65 — the third generation to harvest the mud — has always appreciated how clubhouse attendants apply the mud in their own unique way. But standardization is also good for business:

"The fact that they're trying to get a uniform process with the mud tells me that they know they need it."
— Bintliff, via SI
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