BURLINGTON CO., New Jersey (WPVI) -- When pitchers across Major League Baseball take to the mound, they rely on a secret ingredient that comes from a fishing hole in southern New Jersey.
The special mud they put on the baseball is one-of-a-kind and has quite the history behind it.
It also contains a big secret.
While we know it comes from a small tributary of the Delaware River in Burlington County, only five people in the world know the exact location.
Lena Blackburne Baseball Mud is named for the Philadelphia Athletics coach. Back in the 1930s, he used mud from his favorite fishing hole to add grip to slippery new balls after a batter died.
"They'd spent years with different substances trying to find the right mix," says Jim Bintliff, who now runs the business out of his house with his wife Joanne.
"Everything they tried either damaged the leather or it discolored the ball too much to make it usable."
Jim's grandfather was friends with Blackburne and took over the company in the 1960s. Others have unsuccessfully tried to replicate this "magic mud."
"A lot of people have tried other muds, other dirts," Bintliff says. "Rawlings tried to create a synthetic mud that bombed. The area where we get it is just unique and the minerals are unique to that area."
It's a natural treasure with an undisclosed location.
Bintliff says it's like making a fine wine, except with mud, buckets, trash cans, and a secret treatment.
Every major and minor league team uses his mud and most of the NFL, including the Philadelphia Eagles.
Lena Blackburne Baseball Mud is so vital to the sport, it's on display at the Baseball Hall of Fame in Cooperstown.
"Magic mud" used by every Major League Baseball team is harvested in south Jersey