Baseball Obstruction Rules

Baseball Obstruction Rules

In baseball, obstruction occurs when a fielder without the ball prevents an offensive player from running the basepaths. Obstruction often looks extremely similar to a legal play and doesn’t require physical contact, but the fielder has to have the ball before making the defensive play. This guide is designed for you to learn what obstruction is, be able to identify it both on the field and on TV, and hopefully help you avoid it.


Per Rule 6.01(h) of the official MLB Rulebook, obstruction occurs when a fielder who doesn’t possess the ball impedes the progress of a base runner who is legally within the basepaths. The fielder must be in the process of fielding the ball before they can get in the way of the runner.

Obstruction shouldn’t be confused with interference, in which an offensive player prevents the fielder from making a defensive play. Announcers confuse them all the time on broadcasts, but put simply, obstruction is a penalty on the fielder, while interference is a penalty on the batter-runner. Think of the word “obstruction” as a player who won’t get out of the way, compared to “interference,” where a player goes out of their way to get in someone else’s.


When the umpire calls obstruction, and the ball is in the possession of the fielding team, the umpire signals for time to pause the play. This is considered a Type 1 Obstruction. The runner who has been obstructed is awarded an “advance of base:” that is, if they were headed from first to second base, they’ll be placed on second.

If there are multiple runners on the basepaths, all of them are awarded the next base. So, if one runner is obstructed on the way from first to second, a runner headed home from third will be able to score.

The umpire cannot call time for obstruction if the baseball is in the air. If it’s a wild throw sailing into the outfield, the obstructed runner might get farther anyway if play is allowed to continue. Per Rule 6.01(h)(2), the umpire also won’t call time if a play is being made on a different runner; instead, the umpire will instead wait until “no further action is possible” to dish out the obstruction penalty. This is what’s known as a Type 2 Obstruction call, and it allows the pace of play to continue as normal for as long as it can.

Both Type 1 and 2 Obstructions are non-reviewable plays, so the manager can’t challenge the call made on the field.


  • During a “rundown” situation, in which the runner is caught between first and second base, the fielder without the ball can’t hold the runner up on the basepaths. The runner is always awarded the next base if they’re obstructed, even if they’re scrambling back to first.
  • The ball slips past a diving shortstop, but the shortstop stays down on the basepaths. If there’s a runner going from second to third, the shortstop is obstructing them.


The rules on obstruction date back to when “baseball” wasn’t a single word: they were codified in the laws of the National Association of Base Ball Players in 1857. Mid-19th century baseball clubs in New York City decided that, in order to advance the sport, it required a unified ruleset. Since being included in that ruleset, obstruction has stayed roughly the same for over 150 years, up to the penalty of awarding the runner a free base. So, even as players and fans today get confused when the umpire calls time, obstruction is a rule that’s endured nearly unchanged for over a century and a half.

Similar Rules to Obstruction


What is obstruction in baseball?

Obstruction is called when a fielder who doesn’t have possession of the ball, nor is in the process of fielding it, prevents a runner from getting to the next base. Though it’s similar and often confused with interference, obstruction is a penalty on the fielder, while interference is a penalty on the runner. After the play is dead, obstruction is penalized by awarding the next base to the runner. No matter how confused the manager gets, the call is non-reviewable.