A baseball diamond has three square bases and a five-sided plate. The dimensions for each are spelled out in the Official Rules of Major League Baseball, and they carry down to all levels of baseball. Even when other field dimensions change to accommodate younger players, the bases remain the same size.
Bases
First, second and third base are squares, 15 inches on every side. According to the Major League Baseball rule book, the bases are white canvas bags stuffed with a "soft material" so that they are between 3 and 5 inches thick. The bases are secured to the ground to keep them from moving around when players step on or slide into them.
Home Plate
Home plate is a five-sided slab of "whitened rubber." The rule book describes it as a 17-inch square from which two corners have been removed so that it has a flat end and a pointed end. The flat end is 17 inches long; the two sides adjacent to that end are each 8.5 inches long, and the two sides that form the point are each 12 inches long. The plate is set flush with the ground, with the flat side facing the pitcher and the point facing the catcher.
Layout
The first- and third-base foul lines extend from the point of home plate. At the professional, college and high school levels, it's 90 feet from home plate to first base and to third base, and 90 feet from each of those bases to second base. Youth leagues often play on smaller diamonds, but with 60, 70 or 75 feet between the bases, depending on the age of the participants. Regardless of the size of the diamond, the bases and home plate stay the same size.
Other Dimensions
Beyond the size and placement of the bases and home plate, there are no "standard" dimensions for a baseball field. Major League Baseball sets minimum rules for how far the outfield fences must be -- at least 325 feet down each foul line and 400 feet to straightaway center -- and requires that there be at least 60 feet of foul territory between the infield base paths and the stands or any other obstruction. Some youth leagues set smaller minimums, but beyond that, nearly anything goes. The outfield can be as big as a team cares to make it and doesn't have to be symmetrical. The Houston Astros' stadium even has an uphill slope in centerfield instead of a warning track.
Member Comments