Why Baseballs Are Rubbed With Mud Before Every Game / Where the mysterious Delaware River mud comes from and why MLB still uses it..

Before every Major League Baseball (MLB) game, all baseballs are rubbed with a special mud to remove their slick, glossy surface and improve grip for pitchers. This practice dates back to the 1930s and continues today — and the mud used is famously sourced from a secret location along the Delaware River.

The Reason for the Mud

When baseballs come out of the box, their leather is coated with a shiny, slippery finish that makes them difficult to control. In the early days, players and umpires tried using substances like tobacco juice, shoe polish, or dirt to dull the shine, but those methods often damaged the ball or made it too dark.

In 1938, a Philadelphia Athletics coach named Lena Blackburne discovered a fine, smooth mud from a tributary of the Delaware River near his home in New Jersey. The mud had just the right texture — it removed the gloss without scratching or discoloring the leather. Blackburne began selling it to MLB teams, and soon every team in the league was using what became known as Lena Blackburne Baseball Rubbing Mud.

The Source of the Mud

The exact location of the mud’s source is still a closely guarded secret. It’s said to come from a specific spot along the Delaware River, where the sediment has a unique composition — a fine, silky texture with just the right balance of grit and smoothness. The mud is collected, cleaned, and aged before being distributed to MLB teams.

Why MLB Still Uses It

Despite technological advances, MLB continues to rely on this natural mud because:

• Consistency: It provides a uniform, reliable feel that pitchers have trusted for decades.

• Tradition: It’s part of baseball’s longstanding rituals and superstitions.

• Performance: No synthetic alternative has yet matched its ability to dull the ball’s surface without damaging it.

That said, MLB has been experimenting with other ball-preparation methods in recent years, including factory pre-treatments, but as of now, the Delaware River mud remains the standard — a small but enduring mystery at the heart of America’s pastime.