NOTE: Rule numbers in blue or black (like this: 3.06, or this: 7.02(a)) follow the new OBR rule and numbering scheme introduced in the 2015 Official Baseball Rules. The rule numbers in red type (like this: [3.04]) are corresponding rule numbers from the Official Rules prior to 2015. All of the content has been updated to the 2016 rule book.
2.01 Layout of the Field
[1.04] The field shall be laid out according to the instructions below, supplemented by the diagrams in Appendices 1, 2, and 3.
[1.04] The infield shall be a 90-foot square. The outfield shall be the area between two foul lines formed by extending two sides of the square, as in diagram in Appendix 1. The distance from home base to the nearest fence, stand or other obstruction on fair territory shall be 250 feet or more. A distance of 320 feet or more along the foul lines, and 400 feet or more to center field is preferable. The infield shall be graded so that the base lines and home plate are level. The pitcher’s plate shall be 10 inches above the level of home plate. The degree of slope from a point 6 inches in front of the pitcher's plate to a point 6 feet toward home plate shall be 1 inch to 1 foot, and such degree of slope shall be uniform. The infield and outfield, including the boundary lines, are fair territory and all other area is foul territory.
It is desirable that the line from home base through the pitcher's plate to second base shall run East-Northeast.
It is recommended that the distance from home base to the backstop, and from the base lines to the nearest fence, stand or other obstruction on foul territory shall be 60 feet or more. See Appendix 1.
When location of home base is determined, with a steel tape measure 127 feet, 3-3⁄8 inches in desired direction to establish second base. From home base, measure 90 feet toward first base; from second base, measure 90 feet toward first base; the intersection of these lines establishes first base. From home base, measure 90 feet toward third base; from second base, measure 90 feet toward third base; the intersection of these lines establishes third base. The distance between first base and third base is 127 feet, 3-3⁄8 inches. All measurements from home base shall be taken from the point where the first and third base lines intersect.
The catcher's box, the batters' boxes, the coaches' boxes, the three-foot first base lines and the next batter's boxes shall be laid out as shown in the diagrams in Appendices 1 and 2.
The foul lines and all other playing lines indicated in the diagrams by solid black lines shall be marked with paint or non-toxic and non-burning chalk or other white material.
The grass lines and dimensions shown on the diagrams are those used in many fields, but they are not mandatory and each club shall determine the size and shape of the grassed and bare areas of its playing field.
NOTE (a): Any Playing Field constructed by a professional club after June 1, 1958, shall provide a minimum distance of 325 feet from home base to the nearest fence, stand or other obstruction on the right and left field foul lines, and a minimum distance of 400 feet to the center field fence.
NOTE (b): No existing playing field shall be remodeled after June 1, 1958, in such manner as to reduce the distance from home base to the foul poles and to the center field fence below the minimum specified in paragraph (a) above.
2.02 [1.05] Home Base
Home base shall be marked by a five-sided slab of whitened rubber. It shall be a 17-inch square with two of the corners removed so that one edge is 17 inches long, two adjacent sides are 8-1/2 inches and the remaining two sides are 12 inches and set at an angle to make a point. It shall be set in the ground with the point at the intersection of the lines extending from home base to first base and to third base; with the 17-inch edge facing the pitcher's plate, and the two 12-inch edges coinciding with the first and third base lines. The top edges of home base shall be beveled and the base shall be fixed in the ground level with the ground surface. (See drawing D in Appendix 2.)
2.03 [1.06] The Bases
First, second and third bases shall be marked by white canvas or rubber-covered bags, securely attached to the ground as indicated in Diagram 2. The first and third base bags shall be entirely within the infield. The second base bag shall be centered on second base. The bags shall be 15 inches square, not less than three nor more than five inches thick, and filled with soft material.
2.04 [1.07] The Pitcher's Plate
The pitcher's plate shall be a rectangular slab of whitened rubber, 24 inches by 6 inches. It shall be set in the ground as shown in Diagrams 1 and 2, so that the distance between the pitcher's plate and home base (the rear point of home plate) shall be 60 feet, 6 inches.
2.05 [1.08] The Benches
The home club shall furnish players' benches, one each for the home and visiting teams. Such benches shall not be less than twenty-five feet from the base lines. They shall be roofed and shall be enclosed at the back and ends.