Most baseball fans feel they know the rules, but many of them are actually misunderstood, at least their nuances and technical definitions. Even you are fairly well-versed in the rulebook, a primer never hurts, so BP asked the MLB Umpiring Department about 10 of them. Major League Baseball umpire supervisor Charlie Reliford, a 19-year major-league umpire, and Major League Baseball umpire supervisor Larry Young, a 23-year major-league umpire, provided the definitions and clarifications.

Today, we’ll wrap things up and look into discretionary calls, interference, “neighborhood” calls, the strike zone, rule changes, and instant replay. You can also view Part I, Part II, Part III, and Part IV.

Discretionary Calls

Charlie Reliford: Most infractions carry specific penalties in the rulebook. One that does not is spectator interference. Many believe that when a person not authorized to be on the field touches a ball in play that it is a ground rule double.

2.00(d) Spectator interference occurs when a spectator reaches out of the stands, or goes on the playing field, and (1) touches a live ball or (2) touches a player and hinders an attempt to make a play on a live ball.

3.15 No person shall be allowed on the playing field during a game except players and coaches in uniform, managers, news photographers authorized by the home team, umpires, officers of the law in uniform and watchmen or other employees of the home club. In case of unintentional interference with play by any person herein authorized to be on the playing field (except members of the offensive team participating in the game, or a coach in the coach’s box, or an umpire) the ball is alive and in play. If the interference is intentional, the ball shall be dead at the moment of the interference and the umpire shall impose such penalties as in his opinion will nullify the act of interference.

When fan interference occurs, the umpire’s first decision is whether the person was authorized to be on the field, such as a batboy, ball girl, police officer, or whether it was fan who reached over a fence or railing. A person who is authorized to be on the field has not committed interference without intent. If the ball just touches him or her accidentally or he or she interferes with a player making a play, no violation has occurred unless the umpire judged that they did it intentionally. A good example would be a batted or thrown ball accidentally deflecting off a batboy as opposed to picking up a live ball. With a fan or other person not authorized to be on the field, intent is not the question; where the interference occurred is the question. If the fielder reaches into the stands, he does so at his own peril. If the fan reaches, it is then just the judgment by the umpire whether the fan interfered.

A batted ball that bounces into the stands would be a double by the rulebook. A batted ball that would have bounced into the stands but was interfered with by a fan might be ruled a double because that would have been what would have happened had the fan not interfered, whereas a ball interfered with by a fan close to the infield might be ruled a single, and a batted ball that reaches the outfield corner might be ruled a triple.

On a ground-rule double, all runners, including the batter-runner, are awarded two bases from the time of the pitch regardless of where the umpire believes they would have reached. On interference the umpire may call outs, give one runner multiple bases while keeping another runner at his original base. The umpire is to make whatever award is necessary to nullify the act of interference.


Larry Young: A fielder attempting to make a play has the “right of way.” If a runner impedes, confuses, or runs into that fielder, the runner will be called out for interference. All other runners must return to the bases they occupied at the time of the interference.

If the fielder is not attempting to make a play, he must get out of the way of the runner. The runner now has the “right of way.” The penalty for obstructing the runner is subjective and requires a judgment by the umpire. The runner will be awarded the base or bases he would have reached had there been no obstruction.

“In the area” calls at second base on force outs

Larry Young: There is no such thing as an area call at second base. The fielder attempting the force play at second must touch the base to record an out. Professional baseball players are skilled in “turning the double play” so that they touch the base, and then clear themselves from the sliding runner in order to avoid injury.

The Strike Zone

Larry Young: The strike zone has changed several times in the history of baseball. It is now defined in the following three areas:

  1. Width: Any portion of the baseball that crosses the 17-inch wide plate should be deemed a strike.
  2. Low end: Any ball that passes through the hollow beneath the kneecap.
  3. High end: Any ball that passes through a line halfway between the shoulder and the top of the uniform pants.

Rule Changes

Larry Young: Parts of the original rules written in the 1800s still exist in the 2011 Official Baseball Rules. Rules can be changed by the nine-member Playing Rules Committee. The committee meets each year at the annual baseball Winter Meetings. Suggestions for rule changes can come from umpires, players, baseball executives, and even fans.

At the MLB level, MLB consults the Players Association on any proposed rule, and the MLBPA has a role in the approval and implementation of any proposed rule. If the MLBPA has a particular issue or concern with a proposed rule, usually the Rules Committee will further study the proposal.

The MLB umpires union, which is called the World Umpires Association, has the authority to place an active umpire on the Playing Rules Committee. The Players Association is also represented by a former player.

Instant Replay

Larry Young: Instant replay has proven to be an effective officiating tool to aid umpires in boundary calls. Video replay is now limited to boundary calls. These calls are fair/foul above the fence, commonly called “pole benders,” in reference to the foul pole. Also reviewable are home run versus spectator interference calls near the fence. The crew chief is the sole judge in determining whether to use the video replay.

 The future use of instant replay, including potential expansion for other kinds of plays, is solely at the discretion of the commissioner of baseball.