MLB Tightens Protocol, Requires Uniform Technique to ‘Muddy’ Baseballs

The league is officially setting a standard for muddying baseballs, which teams do before games to reduce the slickness of the leather.

MLB is continuing to tighten the protocols of rubbing baseballs with mud before games to reduce the slickness of the leather, according to a source familiar with the regulations.

The changes began midway through last season and resulted in more uniform condition of the baseballs. Home team employees rub the baseballs. Some did so as early as 24 hours before the game and stored them in large bags. Pitchers found that the baseballs used late in games—the ones from the bottom of the bag—often were the slickest because the mud had dried and dusty residue from other baseballs or the bag itself settled on them.

Full Winter Meetings Notes: Verducci’s Day 2 here.

MLB last year recorded video of how each home employee rubbed the baseballs, and saw many different techniques and results. MLB found the one technique it believes works best and set that as the new template. The league also limited the process to three hours before the game, limited the baseballs stored in each bag to eight dozen and ordered the bags to be cleaned regularly—which limits the incidental dried, dusty residue that was landing on baseballs.

MLB also distributed photographs of three rubbed baseballs in varying colors—lightly rubbed, medium and darker—and established the preferred template as more toward the darker version. Baseball continues to experiment with tackier leather and a spray-on substance, but neither remedy is close to being ready for MLB use.

Want to learn more? Check out Emma Baccellieri's feature about the man whose family business is the rubbing mud for Major League Baseball: Mud Maker: The Man Behind MLB’s Essential Secret Sauce