Why Is Pine Tar Illegal in Baseball?

Rule 3.02(c) says the bat handle, for not more than 18 inches from its end, may be covered or treated with any material or substance to improve the grip. Any such material or substance that extends past the 18-inch limit shall cause the bat to be removed from the game.

A note follows. If the umpire discovers that the bat does not conform to this rule at a time during or after which the bat has been used in play, it is not grounds for declaring the batter out, or ejected from the game.

The comment to the rule is specific about pine tar. If pine tar extends past the 18-inch limitation, the umpire, on his own initiative or if alerted by the opposing team, orders the batter to use a different bat. The batter may use the bat later in the game only if the excess substance has been removed. If no objections are raised before the bat is used, then a violation of the rule on that play does not nullify any action or play on the field.

The bat rule is often confused with the rule that applies to pitchers. The rulebook prohibits a pitcher from applying a foreign substance of any kind to the ball (Rule 6.02(c)(4)) and from having any foreign substance on his person or in his possession (Rule 6.02(c)(7)). That is a separate rule from the one about the bat handle, with its own penalties, which this page does not set out.

So the answer to the question depends on who is using it: on a bat, pine tar is legal within the limit, and on a ball or a pitcher it is not.

The grip rule is one of several measurements for the bat. Rule 3.02(a) says the bat is a smooth, round stick not more than 2.61 inches in diameter at the thickest part and not more than 42 inches long, made of one piece of solid wood. No laminated or experimental bats may be used in a professional game until the manufacturer has secured approval from Major League Baseball of the design and the methods of manufacture, and no colored bat may be used unless approved by Major League Baseball.

The ball has its own specification in Rule 3.01. It weighs not less than five nor more than 5¼ ounces and measures not less than nine nor more than 9¼ inches in circumference. No player may intentionally discolor or damage the ball by rubbing it with soil, rosin, paraffin, licorice, sandpaper, emery paper or another foreign substance, and the penalty is removal from the game and an automatic suspension of 10 games.

The wording comes from Rule 3.02(c) and its comment in the Official Baseball Rules, 2026 edition. The page quotes the rulebook and does not describe individual incidents.

The rules are reviewed each year. This page was checked against the 2026 edition. More baseball pages are collected on the MLB hub.