Baseball's Dirty Secret Comes From a Hole in the Ground

Every baseball used in every Major League game is rubbed with mud before it enters play. This has been true since the late 1930s. The mud comes from a single, secret location along a tributary of the Delaware River in southern New Jersey. One family has been harvesting it for nearly ninety years. Major League Baseball has no alternative.

The story begins with a death. In 1920, Cleveland Indians shortstop Ray Chapman was killed by a pitch to the head, the only on-field fatality in major league history. In the years that followed, baseball made changes to improve player safety, including a rule requiring umpires to remove dirty or scuffed balls from play and replace them with clean ones. But new baseballs had a problem. Straight from the Rawlings factory, they were slick and glossy, difficult for pitchers to grip. A pitcher who couldn't grip the ball couldn't control it, and an uncontrolled pitch at 90-plus mph was exactly the kind of thing that had killed Chapman.

Teams tried everything to take the shine off. They rubbed the balls with infield dirt, but it scratched the leather. They tried tobacco juice, but it stained the balls too dark for hitters to see. They tried shoe polish. Nothing worked well enough.

In 1938, a former player and coach named Russell Aubrey "Lena" Blackburne remembered something from his childhood in Palmyra, New Jersey. Growing up, he had waded in a creek near the Delaware River and noticed that the tidal mud at the bottom had an unusual quality. It was fine-grained, smooth, and slightly gritty, the consistency of thick chocolate pudding. When he was a kid pitching in sandlot games, he used to rub it on new baseballs to get a better grip.

Blackburne went back to the creek, scooped up some mud, brought it to the Philadelphia Athletics' clubhouse, and gave it to umpire Harry Geisel. Geisel rubbed it on a baseball. The gloss came off without scratching the leather or discoloring the cover. The American League adopted it almost immediately. The National League followed within a few years. By the 1950s, every team in professional baseball was using Blackburne's mud.

When Blackburne got too old to harvest the mud himself, he passed the business to his childhood friend John Haas, who had accompanied him on his original searches. Haas passed it to his son-in-law, Burns Bintliff. Burns passed it to one of his nine children, Jim. Jim Bintliff has been running the operation for decades. He harvests roughly 1,000 pounds of mud per year from the same spot, using a shovel and a few buckets. He cleans and screens the mud in his backyard, stores it over the winter, then fills small plastic containers and ships them to every team in the majors and minors the following spring.

The location of the mud is a family secret. Jim Bintliff has never revealed it to MLB. When he's caught at the site by strangers, he tells them the mud is for his garden, or his rose bushes, or for treating poison ivy. His grandfather made Haas promise never to reveal the location. Haas made Bintliff's father promise the same thing. The promise has been kept across three generations.

In 1982, the New York Times commissioned a geological analysis of the mud. Princeton geologist Dr. Kenneth Deffeyes examined a sample and found that more than 90 percent of it was finely ground quartz, likely crushed by glaciers during the Pleistocene Epoch more than 10,000 years ago. In 2024, researchers at the University of Pennsylvania became the first to empirically prove that the mud actually works, designing tests with a synthetic rubber "finger" to measure its friction-enhancing properties.

MLB has tried, on and off, to find a synthetic replacement. Rawlings has experimented with different ball treatments. None have matched the mud. Jim Bintliff, who worked full-time as a printing press operator for most of his career because the mud business brought in only about $20,000 a year, has always known why.

"It's the history and the tradition," he has said. "Every ball, every game, every day."