Introduction
Technology has had a large effect on the game of baseball and softball. In general, equipment performs better and is more reliable than it was just a few years ago. To maintain the integrity of the game, test methods have been developed to regulate some of the technologies used in play. The following will consider the characteristics and test methods of balls and bats.
Until the 1970’s, all bats were made of wood. Aluminum bats were introduced to improve durability. It was soon discovered, however, that some hollow bats could hit a ball further than wood. Bat design and material development have continued at a brisk pace. The technology has benefited the offense and done little for defense. This shift in the nature of the game brought into question the benefits of the new bats. In the late 1990’s, test methods were developed that could be used to regulate bat performance. By 2000 nearly all amateur associations had adopted bat performance tests. While the details of the test varied by association, most were based off of ASTM F1890. After only a few years, short comings of these tests became apparent. An improved method was developed in 2004 and was designated ASTM F2219. The NCAA and ASA have based their performance tests off this new method.
The ball has also evolved with technology. The first softball, for instance was a boxing glove with the laces tied up. Small medicine balls were also used. The ball has evolved a number of times over the years in size and material, including kapok, rubber and cork. Today most baseballs are made from wool yarn wrapped around a cork or rubber pill, while softballs are made from a polyurethane core with a thin leather or synthetic cover. The formulation of the polyurethane is relatively advanced where ball stiffness (ASTM F1888) and elasticity (ASTM F1887) are controlled independently. In the case of baseballs, the design of the pill and tension of the wool windings tend to effect elasticity and stiffness, respectively. These features interact with the performance of the bat in a complex way. Thus, their accurate control is essential toward reliable performance regulation.
The following will review bat and ball test methods and characteristics relevant to regulating performance.
