What is a Rosin Bag?

A rosin bag is a small burlap or canvas bag that is filled with rosin powder, a semi-sticky to sticky substance that helps pitcher’s get a better grip on the baseball. MLB wisely allows pitchers to use rosin to acquire a dry grip for the sake of hitters’ safety.

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A pitcher's mound with a rosin bag laying on it.
That rosin bag looks rather lonely.

Baseball is a game that is primarily played in the hot summer months, where pitchers are working themselves hard to exertion and building up a good sweat. If MLB did nothing for the pitchers, the ol’ Rawlings would slip a bit more out of the hand and end up in a few more on deck circles, where batters would be doing on-field gymnastics to avoid getting drilled with a 93.6mph fastball (the league average in 2022).

What Major League Baseball doesn’t allow is sticky foreign substances. We will get into the specifics regarding rosin powder and why it’s not considered a banned substance shortly. Before we do though, let’s cover where the bag sits on the field.

Check out our Baseball terms guide.

Where is the Baseball Rosin Bag on the field?

The Rosin Bag is located behind the pitcher‘s mound for the purpose of accessibility. A pitcher having to walk back and forth to the Home Plate Umpire would get old, fast. So, MLB tosses the satchel of rosin powder on the down slope of the mound that faces the outfield.

According to SF Chronicle, ”Before every MLB game, two of Phillips’ rosin bags are placed behind the mound by a batboy, one with hard rosin and one with powdery rosin, which Phillips crushes himself with a sledge hammer. Instead of the old style of wrapping rosin in cut-up sanitary socks tied at both ends, the new pouches are hand-made from an Oakland supplier.”

When did the Rosin Bag arrive in MLB?

According to Peter Morris, author of the baseball book, A Game of Inches: The Stores Behind the Innovations That Shaped Baseball, the rosin bag first came to the major leagues in 1887. Morris cites a game report in the Cincinnati Enquirer as the source for the information. He also cites the Sporting News for an 1893 mention of rosin’s existence by pitchers.

Pitchers such as legend Christy Mathewson reported on it’s use in the early 1900s, which was before rosin powder was banned between the years 1919 and 1931, due to MLB labeling the powder a foreign substance.

Rosin Bag vs Pine Tar and Other Foreign Substances

According to ex-Major League Pitcher, Pat Hentgen of the Toronto Blue Jays, rosin was a substance that he, “put on his arm” because of profuse sweating. That’s the kind of thing that MLB takes a look at when deciding upon any rule modifications. It’s how sunscreen, Spider Tack, and all other foreign substances get banned.

However, many hitters prefer to allow the pitcher the advantage, whether real or perceived, because they want the pitchers being able to locate 100% of their pitchers for their own safety.

Nothing is worse than a pitch slipping through the pitcher’s grip and the batter not being able to pick up the pitch in time. Some things are more important than your team’s standings or your hitting performance, whether that’s in the MLB, minor league ball, or your local Little League, and that thing is your health and safety.

Don’t believe us, ask Tony Conigliaro.

Is Rosin a sticky substance?

Yes, rosin is a stick substance. The official rosin that is used by teams such as the New York Yankees, Pittsburgh Pirates, and Boston Red Sox - and well, all the teams - comes from Honduran pine trees.

Is Rosin powder illegal?

No, rosin powder is not illegal for pitchers to use in Major League Baseball. Pitchers like Adam Wainwright of the St. Louis Cardinals need a firm, tight grip if they want to unleash Uncle Charlie (slang for curveball) to an unsuspecting batter.

Who makes Major League approved Rosin Bags?

Once again, according to SF Chronicle, just one company is approved to produce pro quality rosin bags for official MLB play starting in 2022. And that official company is called, Pelican Bat Wax.

It’s owner, Dave Phillips, has secured a two year agreement with league, so good for him. It’s really excellent to see the small business owner from San Francisco get a shot at supplying such a large corporation. Far better than a Rawlings, Easton or Marucci, for sure.

“Major League Baseball has standardized how pitchers use rosin this season, so thousands of rosin bags are being shipped to teams from a single company that obtains, produces and transports the product.”

Pitchers & Coaches throwing Rosin Bags

“I seem to remember last week somebody throwing a rosin bag in my face. Told me to get my fat ass back behind the plate. Was that you or the umpire?” - Dotty Henson, Catcher for the Rockford Peaches, A League of Their Own

I think the quote from Dotty Henson sums up everything you’d ever need to know about a baseball rosin bag and how it gets used. Properly.

Mike Montgomery Throws Rosin Bag in KBO

Ex-Cubs pitcher, Mike Montgomery, got heated and drilled an ump with a rosin bag while being held back by his Samsung Lions teammates on September 10th of 2021. Apparently it was over a dispute concerning the 12 second pitch rule.

Well at least Montgomery connected. Had he not, he still would have gotten the ejection, only without the satisfaction. On second thought, had he possessed that kind of accuracy in the MLB, he might not have had to ship himself overseas to play pro ball.

Phillip Wellman of the Mississippi Braves uses the Rosin Bag as a Grenade

In perhaps the single greatest coach melt down of all-time, Minor League coach, Phillip Wellman (Mississippi Braves) absolutely lost it in 2007, covering the plate with dirt, ripping a base out of its anchoring, and, army crawling toward the pitcher’s mound before throwing the rosin bag as a grenade.

The NFL equivalent of this would be punting the ball through the uprights, stealing a referee’s flags, and perhaps maybe, just maybe, tackling the opposing team’s mascot on your way to the showers.

Unlike minor league baseball umpires, NFL referees get paid well ... so there’s that.

Can College or High School Pitcher use Rosin Bags?

Yes, a college or high school pitcher can use rosin to his or her bare hand for the purposes of attaining a better grip.

References & Sources