Interference is the toughest call an umpire has to make. It is a call based solely on the umpire's judgment. To make a good judgment as to whether or not interference occurred, the umpire must understand the definition as stated in the rules so it can be recognized when it occurs. After interference is called, the proper rule must be applied.

The definition as stated in Rule 2.00 is:

(a) Offensive interference is an act by the team at bat which interferes with, obstructs, impedes, hinders or confuses any fielder attempting to make a play. If the umpire declares the batter, batter-runner, or a runner out for interference, all other runners shall return to the last base that was in the judgment of the umpire, legally touched at the time of the interference, unless otherwise provided by these rules.

In the event the batter-runner has not reached first base, all runners shall return to the base last occupied at the time of the pitch.

(b) Defensive interference is an act by a fielder which hinders or prevents a batter from hitting a pitch."

It should be noted that (b) above is the only defensive interference. Hindering the runner by the defense is OBSTRUCTION. How do we interpret this rule? The key, is to focus on the phrase "interferes with, obstructs, impedes, hinders or confuses." Those words cover a lot of actions. The umpire, after witnessing an act by the offense must ask himself the following question; "Did the offense interfere with, obstruct, impede, hinder or confuse the fielder attempting to make the play?" If the answer is yes, interference should be called. The call must be made as soon as possible. When interference is called the ball is immediately dead and no runners may advance beyond the base they held at the time of the interference. The umpire must be aware of where all runners are at the time of the call. When the interference occurs the umpire immediately calls it. You do not wait to see the outcome of the play.

Some interference calls are easy. Example: If a runner is hit by a batted ball he is out and no judgment of intent is required unless he is hit by a deflected ball, or the ball has passed on infielder, in which case the umpire must decide if he intended to be hit to interfere, obstruct, impede, hinder or confuse the defense or if another fielder had a play on the ball. Rule 5.09(f) and 7.08(f).

Example: A runner MUST avoid a fielder attempting to field a BATTED BALL. If he does not he is guilty. This is a fairly easy call. Rule 7.09(L) and 7.08(b).

The fielder's protection begins the moment the ball is hit. That protection continues as he completes his initial play. His protection ends if he misplays the batted ball and has to move to recover it. Contact with the fielder is not necessary for interference to be called.

When a ball is hit, you have to judge which fielder has the best chance to field the ball. That fielder is then "protected" meaning; must not be interfered with, from the time the ball leaves the bat, up through the gloving of the ball and the act of throwing. The fielder is protected even if he started to field the ball from outside the basepath and then moved into it to field the ball. The runner must avoid a fielder attempting to field a batted ball. Rule 7.09(L). He must avoid the fielder and not interfere with him during the entire time that the fielder is in protected status and in all areas including the basepath.

Interference is the act of hindering or obstructing a fielder attempting to make a play. A "Play" is the act of throwing, or attempting a tag of a runner or a base, or an attempt to catch a throw.

Difficult calls are the ones involving thrown balls. Interference with a thrown ball must be judged as an intentional act. Rule 7.08(b), 7.09(L). If a runner is hit by a thrown ball while running the bases, he is not out unless the umpire judges that the runner intentionally interfered, obstructed, hindered or confused the defense attempting to make a play.

Some examples of interference are:

	Yelling at a fielder as he attempts a catch or play (Note that the rule states "the team at bat.." This includes coaches and players on the bench.)
	Waving his arms to distract the fielder
	Making contact with the fielder as he attempts a throw
	Making contact or otherwise interfering with the fielder as he attempts to catch a batted ball
	Making INTENTIONAL contact with a fielder as he attempts to catch a thrown ball. The runner has a right to the base path except when a fielder is attempting to field a BATTED ball
	Making INTENTIONAL contact with a thrown ball
	Stopping directly in front of a fielder attempting to field a ground ball