For more than 80 years, baseball has relied on special mud stashes to remove the shine from the ball's smooth leather and give fielders a better grip. This substance is applied to all baseballs before major league games.

The mud, called “Lena Blackburn Baseball Rubbing Mud,” comes from a single source: a secret location on the banks of a tributary of the Delaware River. Jim Bintliff, a retired printing press operator in New Jersey, collects mud from his grandfather's old fishing pond about once a month. He likens its consistency after processing to “cold cream or hard pudding.”

Despite mud being ubiquitous, scientists have been unable to explain why mud makes gripping the ball easier, or even provide empirical evidence that mud actually works. Until now.

Researchers at the University of Pennsylvania designed a series of tests to study the mud and even created synthetic rubber “fingers” to measure its properties. their results are Published Monday in the Proceedings of the National Academy of Sciencesprovides the first published scientific evidence that the power of mud is more than a myth.

“It goes on like a face cream, but it grips like sandpaper. It has this magical ability,” said Doug Jeromack, a geophysicist at the University of Pennsylvania and co-author of the study. states.

Jeromac's team found that the mud contains the perfect ratio of sticky clay and sand particles. The latter drives rivets into the surface of the ball like barnacles to increase friction, but the material still spreads thin and evenly like toothpaste.

“The harder you work, the better it flows,” Jeromac says.

The authors concluded that attempts to create synthetic alternatives to mud (something Major League Baseball has researched) are foolish.

“It's a very special combination of ingredients that nature creates that makes it work,” Jeromac said.

Mud's origin story is rooted in tragedy.

In a match in August 1920, New York Yankees pitcher Karl Mays He fired the ball at Cleveland shortstop Ray Chapman, hitting him in the head. ball It hit Chapman in the skull, killing him..

The death raised concerns about wild pitches and the danger of fresh, shiny baseballs slipping out of pitchers' hands. So in 1929, the National League president required umpires to dirty the ball to give it a better grip. According to the Baseball Hall of Fame.

However, finding a suitable substance proved difficult.

“They tried to use infield dirt, which scratched the leather too much. They tried shoe polish and cigarette spit. Those things made the ball too dark,” Bintliff said. .

Finally, in 1938, Philadelphia Athletics third base coach Lena Blackburn remembered the finely filtered dirt of her childhood in New Jersey. He returned to the source, collected it and began to apply it.

The mud was so popular that Blackburn set up a business to process and sell it. Eventually, he handed over the business to a childhood friend with whom he used to fish and swim, and his grandson Bintliff now runs the company with his wife.

Starting in 2022, MLB will require at least 156 balls to be prepared for each game, with at least 156 balls for each game. Scrub mud for 30 seconds within 3 hours.

Bintliff said MLB buys each team a bucket of mud for $100 each, adding two during the regular season and more during spring training. Some clubs, like the World Series champion Dodgers, are purchasing additional containers for their farm systems, he added.

“This mud acts as a super-fine abrasive, removing shiny coatings without damaging the leather or laces,” Bintliff said.

He collects the mud in 5-gallon buckets (usually about 10 to 20 buckets each time he visits the riverbank), drains the river in his garage, removes twigs and rocks, and uses tap water. plus processing. This process yields approximately 150 pounds of product on average.

Are there any special ingredients added?

“It's a proprietary part,” he said.

The scientists who studied the mud are not big baseball fans, but they became interested after conducting an informal analysis of the mud five years ago. Two students from Jeromac's lab then set out to prove whether the mud worked. They developed three important tests.

First, they used an atomic force microscope to analyze the adhesion, or stickiness, of the mud. Atomic force microscopy measures the resistance of the mud as the instrument is pulled away from it. Then, to understand how well the mud was flowing, the researchers placed the mud in a machine called a rheometer, which rotated the sample and measured its viscosity.

The third test estimated the friction between human skin and a baseball. The idea was to make a “finger'' out of synthetic rubber and apply a drop of whale oil instead of the oil secreted by human skin. The “finger” was pressed against a strip of leather baseball and rotated on the rheometer.

Emanuela del Gado, director of Georgetown University's Institute for Soft Matter Synthesis and Metrology, said the properties uncovered in these tests are rare and sought after in cosmetics and other fields.

“Industry spends a lot of time tweaking formulations to get those properties,” said Del Gado, who was not involved in the research.

“Substances that are simple to us can be very complex, and they can tell us a lot,” she adds, adding that mud is a product of long cycles of flow, rainfall, and seasonal environmental changes. It was pointed out that it was formed by

These days, Bintliff's clients include college coaches, Little League umpires, and National Football League teams. He plans to pass the business on to one of his children.

So far, mud has withstood the new technologies competing to replace it.

In 2016, MLB tested balls coated with proprietary chemicalsAnd last year, commissioner Rob Manfred announced that the league was working with Dow Chemical to We will develop a “sticky ball'' that remains “pure white''. But MLB officials say the project is still no closer to an alternative solution to mud.

The study authors recommended keeping the mud in place because of new evidence that confirms what baseball players intuited more than 80 years ago: “This works,” Jeromac said.