Obstruction (baseball)

In baseball, obstruction is when a fielder illegally hinders a baserunner running within the basepath.

Baserunners are generally permitted to run from base to base without being physically blocked or hindered by a fielder. The only time that a fielder is not obligated to "get out of the way" of a baserunner is when the fielder is fielding or in possession of the ball.

Official Baseball Rule 2.00 defines obstruction as:

The act of a fielder who, while not in possession of the ball and not in the act of fielding the ball, impedes the progress of any runner.

Comment: If a fielder is about to receive a thrown ball and if the ball is in flight directly toward and near enough to the fielder so he must occupy his position to receive the ball he may be considered "in the act of fielding a ball." It is entirely up to the judgment of the umpire as to whether a fielder is in the act of fielding a ball. After a fielder has made an attempt to field a ball and missed, he can no longer be in the "act of fielding" the ball. For example: an infielder dives at a ground ball and the ball passes him and he continues to lie on the ground and delays the progress of the runner, he very likely has obstructed the runner.

The comment to Rule 7.09(j) adds that

[o]bstruction by a fielder attempting to field a ball should be called only in very flagrant and violent cases because the rules give him the right of way, but of course such right of way is not a license to, for example, intentionally trip a runner even though fielding the ball.

High school and college versions of the rule also add rules against malicious or flagrant contact.

Any case of obstruction falls into one of two categories generally called type "A" and type "B", after the subsection of Rule 7.06, in which each type of obstruction, and the corresponding penalties, are described.

Type A:

If a play is being made on the obstructed runner, or if the batter-runner is obstructed before he touches first base, the ball is dead and all runners shall advance, without liability to be put out, to the bases they would have reached, in the umpire’s judgment, if there had been no obstruction. The obstructed runner shall be awarded at least one base beyond the base he had last legally touched before the obstruction. Any preceding runners, forced to advance by the award of bases as the penalty for obstruction, shall also advance without liability to be put out.

Type B:

If no play is being made on the obstructed runner, the play shall proceed until no further action is possible. The umpire shall then call “Time” and impose such penalties, if any, as in his judgment will nullify the act of obstruction.

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Wikipedia