Awarding Bases

   The Pitcher, Mound, and Dimensions

Of the triad at the core of baseball (batting, fielding, and pitching), pitching is far and away the most complex. This is true not just for players and coaches, but for umpires as well. There are a lot of rules governing pitchers and pitching, and many of them are nuanced.

Aspects of umpiring like working the plate, calling balls and strikes, and particularly seeing and calling balks, take time and experience. Even a seemingly silly question like "When is a pitcher not a pitcher?" is actually an important and meaningful question.

In fact, umpiring pitchers and pitching is so broad a topic that we cover it over four articles. The present article, The Pitcher, is first in the series. The remaining three are:


What is a pitcher?

That sounds like a stupid question, but it's not. To get at the answer, let's start with the rule book: Definitions (pitcher): "… the fielder designated to deliver the pitch to the batter." 

Simple enough. But there's more to it. The player designated in the lineup "to deliver the pitch to the batter" is only a pitcher (technically) when he is in contact with the pitching plate. When that player is not in contact with the pitching plate (the "rubber"), the player is no longer (technically) a pitcher, but rather just a defensive fielder.

So to recap, the pitcher is the player designated on the lineup to deliver the pitch; but then we learn that he's only really a pitcher when in contact with the pitching rubber, and that at all other times on defense, he's simply another fielder. What gives?

What gives is that there are several pitching rules and prohibitions that apply to the pitcher when (and only when) he is in contact with the rubber. When he is not in contact with the rubber, he's simply a defensive fielder and those pitching rules no longer apply. For example, while not engaged (that is, while he's a fielder), the player can fake a throw to any base. When engaged to the rubber, however (when he's a pitcher), faking a throw to a base is almost always a balk.

The matter of what a pitcher can and cannot do depends on two things. First, as we've said, it matters whether the "pitcher" is a pitcher or a fielder – that is, whether he is in contact with the rubber or not. Second, the pitching rules vary depending on whether the pitcher is in the windup position or the set position. And finally, which rules apply depend also on the point in the pitching sequence the pitcher has reached.

We go into detail on the pitching positions, the pitching regulations with respect to the pitching positions, and then about balks and illegal pitches in the two companion articles, The Pitching Positions and Balks & Illegal Pitches.


The pitcher's mound

On a regulation baseball diamond, the pitcher's mound measures 18' in diameter. The flat area atop the diamond, called the table, measures 5 feet wide by 34 inches deep. Six inches from the front edge of the table is the pitcher's plate (also called the rubber), which measures six inches deep by 24 inches wide.

pitcher's moundThe distance from the front edge of the pitcher's plate to the rear point of home plate measures 60'-6". This distance was established in 1893 and has served baseball well for 125 years. The height of the mound, however, has changed – most recently in 1969, when it was lowered to its present height of 10 inches. From the front of the table, the mound slopes down such that it loses one inch of height for every foot nearer to home plate.

These dimensions are the ideal, of course, and on professional fields an army of groundskeepers do well to maintain the proper dimensions. But a pitching mound is a difficult piece of ground to maintain, and on amateur fields you are most often lucky to see a mound that is wholly conforming to the regulations.


Field dimensions in amateur baseball

One measurement that does not (or should not) vary, however, is the distance from the front edge of the pitcher's plate to the rear point of home plate. As we said, on a regulation field, this distance is 60'-6". This distance changes only by rule, depending on league and the age level of the players.

Following are the most common pitching and field dimensions.

  • Regulation field. As we've said, on a regulation field the pitching distance is 60'-6". The distance from base to base (the base path) is 90'. Regulation fields are used in professional baseball, of course, but also in college, high school, and most youth leagues whose players are about 15 and older.
  • 54/80. Pony Baseball's Pony division (13-14 year olds) play on fields whose pitching distance is 54 feet and whose base paths measure 80 feet.
  • 50/70. Little League introduced a new "Intermediate" division in 2012 for players from 11-13 that uses a 50-foot pitching distance and 70-foot base paths. Cal Ripken also has a 50/70 division for 11-12 year olds, and Pony Baseball uses these dimensions for its Bronco division (11-12 year olds).
  • 46/60. A pitching distance 46 feet (with 60-foot base path) is standard for Little League divisions where the players are 12 and under. These dimensions are also common for other youth leagues whose players are 12 and under.

    Note: Umpire field mechanics on playing fields measuring 50/70 and larger tend to be consistent, so throughout we will use the term "big diamond" to refer collectively to fields that are 50/70 and larger. Mechanics on 46/60 fields, however, are quite different, so we'll refer to 46/60 fields as "small diamond."