Geology's Grip on Baseball: A Geological Characterization of Baseball Rubbing Mud

Major League Baseball (MLB) prepares 156 baseballs for each game by rubbing each ball with a specific mud, sourced from a single company. Lena Blackburne Baseball Rubbing Mud has been the sole supplier of this mud since the 1950’s (“Our Story”), and is stated to be sourced from a tributary of the Delaware River (“Our Story”). The mud is intended to add grip to slippery new baseball leather, and the company describes the consistency as a “cross between chocolatepudding and whipped cold cream” (“Our Story”). Recent studies have attempted to characterize the aerodynamics of mud-rubbed baseballs, as well as to quantify the frictional forces between fingers and baseballs, but do not adequately address the detailed texture, composition or impact of this specific rubbing mud. Another study by Pradeep et al. (2024) studiesthe rheology of the rubbing mud, but does not adequately characterize the sedimentological characteristics of the mud itself or fully assess the changes to the surface of the baseballs. Presented here is a multi-scale geological characterization of the Lena Blackburne Baseball Rubbing Mud, and its impact to the surface of a baseball.