The science behind storing baseballs in humidors

At home, you probably don’t put much thought into where you stash your kids’ fast-pitch softballs or little league baseballs. As long as you’re not tripping over them, those balls are just fine where they’re at—in the trunk of your SUV or tossed in a bin that lives in the garage, right?

But the professionals? They’re putting a lot of thought into baseball storage. In fact, two MLB teams—the Colorado Rockies and now the Arizona Diamondbacks—are turning to humidors to store baseballs. The Colorado Rockies have been employing the strategy for about 15 years. And now the Diamondbacks announced this season they too have plans to install a grandiose humidor at Chase Field.

The idea is keeping baseballs in a humidor helps prevent balls from drying out, and thus carrying farther in high-elevation parks, ultimately driving up the game scores. In fact, Coors Field had earned the nickname “Coors Canaveral” in the early-2000’s, before humidors were used for storage, because so many home runs were being scored in the park. It raises the question: Are pitchers reluctant to play for teams in high-elevation cities because it could skew their stats, pulling down their “Earned Run Average,” or ERA?

Here at Closetbox, we geek out on the science of storage, so let’s dig a little deeper.

  • First a primer: A row of seats at Coors Field, where the Rockies play, are denoted as sitting at exactly 5,280 feet, or a Mile High. That’s a reminder that Denver’s air is 20 percent less dense than air at sea level, which means batted balls can travel further and how Coors Field has become known as a hitter’s heaven. The balls stored in a humidifier, which is legal under the MLB rules, are denser and a little bit larger.
  • By storing balls in humidors, the Rockies have reduced the distance fly balls travel by about 3 to 4 feet, according to John Bohn, an associate research professor in physics at the University of Colorado, and Ed Meyer, a former doctoral candidate at the time of the study. The Nov. 2008 study was funded by a grant from the National Science Foundation and it was published in the American Journal of Physics.
  • Since many home runs just barely make it over the fence, decreasing the distance of fly balls by 3 to 4 feet could reduce the number of home runs scored in the park by 20 percent er game, according to Bohn.
  • But, prior to employing humidors, pitchers in Coors Field had complained about how slippery balls were. “An intriguing possibility is that the humidified balls are easier to grip, allowing pitchers to put a greater spin on a humid ball than on a dry one,” Bohn says. Prior to the humidors, pitchers dreaded throwing in Denver because the thin air was blamed for the lack of break of a curveball or slider, Bohn said.
  • Another scientist, Alan Nathan, professor emeritus of physics at the University of Illinois at Urbana-Champaign, though, makes a point that the humidors could have even a bigger effect. For the first seven seasons at Coors, Nathan points out, there were 3.20 home runs hit per game compared to 1.93 per Rockies away game. When the Rockies began storing their baseballs in a humidor at 50 percent relative humidity, compared to the more typical 30 percent humidity in Denver, the ratio decreased. From 2002 to 2010, the home run hits per game went down to 2.39, which is a 25 percent reduction.

Do we have you re-thinking your sports storage solutions? While we can’t promise you’ll pitch a better game at the company picnic if you store the game balls in a humidor, we can offer you some storage solutions from the pros to keep your gear more organized.


  • Your garage is your basecamp for all sporting adventures. Maybe you’re coaching your daughter’s soccer team and have a stash of orange cones for agility drills, plus the family’s fleet of mountain bikes and an array of skiing and snowboarding gear. Is there even room for the cars? Let Closetbox store your out-of-season gear. For example, we can store your winter sporting equipment in the summer so you’ve got room for all the gear you need for your summer adventures. If it’s basketball season, let us hold on to all the football gear.
  • When you’re setting up an organization system in your garage, skip over the plastic sports organizing systems, suggests Ben Soreff of House to Home Organizing in Norwalk, Conn. They tend to be flimsy and tip over. “We recommend simply using a 5-gallon bucket or even a tall trash can to store hockey sticks, baseball bats and fishing poles,” Soreff says. “We want the system to be easy since when kids run back in for dinner, they usually leave the sports equipment all over the lawn and driveway.” Balls can go in clear bins, he suggests, and rollerblades can be placed on shelves.
  • Got some baseball and softball players in your household? Head to the local liquor store and pick up cardboard boxes that liquor was originally shipped in, suggests Stacey Agin Murray, a professional organizer with Organized Artistry in Fair Lawn, New Jersey. (Aside from working with clients, she has two boys ages 7 and 11 and gets a ton of practice organizing their sporting gear). She suggests finding a box with the separators left inside (which once was used to store bottles in the box). You can place a bat in each hole, and then the sections can be used to store loose or packaged tennis balls, baseballs, softballs, etc., Murray says.
  • “Grouping ‘like’ with ‘like’ is a basic organizing principle,” Murray says. “It makes perfect sense for sporting equipment.” For example, all tennis rackets and balls should be kept together in one spot. All ski equipment gets housed together, Murray says. “Organizing ‘like’ with ‘like’ sporting equipment makes it easier to find when you’re getting ready for a practice or tournament.”