National Collegiate Athletic Association

The NCAA News - News and Features

December 8, 1997

Expert recommends compliance program for bat performance

BY THEODORE A. BREIDENTHAL
STAFF WRITER

The NCAA should adopt a rigorous compliance program and sponsor a scientific field study to document current baseball and softball bat and ball performance, according to an independent expert who directed a year-long review and research program for the Association.

Those steps, recommended by project director Joseph J. "Trey" Crisco III, would form the foundation for future testing that would allow the NCAA Baseball and Softball Rules Committees to develop permanent bat-performance standards based on published, scientific evidence rather than beliefs or anecdotal information.

The recommended compliance program would require manufacturers to test bats and balls in the laboratory using existing American Society for Testing and Materials (ASTM) methodology and the Baum Hitting Machine methodology, Crisco said.

Crisco is director of the bioengineering laboratory at Rhode Island Hospital and Brown University and cofounder of the National Institute for Sports Science & Safety.

The ASTM method -- which measures bat performance by the Bat Performance Factor (BPF) -- was developed by Richard A. Brandt, a professor of physics at New York University, to measure the performance of bats for slow-pitch softball. The BPF testing method measures the velocity of a stationary, yet free-swinging bat, after it is hit by a ball traveling 60 miles per hour. The BPF of a solid wall is considered 1.00.

The interim bat performance standard adopted by the NCAA Baseball Rules Committee in 1995, based on the recommendation of the Sporting Goods Manufacturers Association, allows for a maximum BPF of 1.14, with a margin of error of .01.

The Baum Hitting Machine methodology, developed recently by Steve Baum, president of Baum Research and Development in Traverse City, Michigan, measures batted-ball velocities for any combination of pitch speed and swing-speed velocities.

Crisco recommended that data from both tests should be collected and analyzed by an independent party separate from the NCAA and bat manufacturers. He also recommended that the manufacturers cover the costs associated with testing, data collection and analysis. The costs to the NCAA, he said, would be minimal.

A scientific field study, Crisco said, would complement the compliance program by studying current batted-ball velocities and swing-speed velocities using advanced methods (for example, high-speed, three-dimensional video tracking) and a statistically sufficient sample size. Crisco said this type of information would yield crucial data that could serve as the "gold standard" for evaluating these laboratory test methods.

Other recommendations

In addition to the compliance program and the field test, Crisco recommended the expansion of the NCAA Injury Surveillance System from the current sampling levels of 14 percent and 18 percent of NCAA member institutions that sponsor baseball and softball, respectively, to include a greater percentage of programs.

Finally, Crisco recommended that the NCAA, in conjunction with other organizations like ASTM, Major League Baseball and the National Federation of State High School Associations, host a scientific meeting on bat-ball performance that would allow all interested parties the opportunity to submit their studies for publication and present the findings in a public forum.

All interested parties should be encouraged to participate, Crisco said, with the intent to build a database of bat and ball performance research that can be published.

The recommendations and summary (see accompanying box) also apply to fast-pitch softball bats; however, there is less history in softball product design and even less available data on softball bats and balls, Crisco said. Several other governing bodies, including the Amateur Softball Association, already are addressing the same concerns that motivated his research.

Summary

Following is the summary of the final report of the NCAA Research Program on Bat and Ball Performance:

  • While scientific studies can provide an understanding as to the factors leading to injury from the batted ball, only the governing bodies can define the level of risk that is acceptable for injuries due to batted balls.

  • The exact level of acceptability (typically defined in terms of one or more standard laboratory measurements, such as maximum batted-ball velocity) will be arbitrary but should fall within the values suggested by different scientific studies.

  • Existing standards for baseball bat and ball performance are based on practical experience with little scientific backing.

  • Extensive data from studies on impact injuries to a wide range of tissue (e.g., muscle, bone, brain) and on the reaction times of subjects clearly indicate that increases in impact velocity would increase the severity and the frequency of injury.

  • Injuries from the batted ball have occurred with the use of wooden bats and traditional baseballs.

  • Baseball and softball remain the safest sports (as defined by the frequency of injury) of those sports included in the NCAA Injury Surveillance System (ISS).

  • The NCAA ISS reports that the frequency of injuries from batted balls has remained constant since 1992.

  • No rigorous, scientific studies on bat performance have been published. The limited data that are available indicate that modern nonwood bats outperform comparable wood bats, as defined by maximum batted-ball velocity.

  • In its present form, the existing standard test method for estimating bat performance -- the BPF -- is not likely to predict actual batted-ball velocities in baseball or fast-pitch softball. This opinion is based on the fact that the test pitch velocity is set at 60 miles per hour with no swing-speed velocity. This is compared with velocities from the bat-ball collision in baseball that can reach 150 mph in game-like conditions. Data provided by two different laboratories suggest that this limitation cannot be corrected simply by increasing the pitch velocity. There was significant variability at three laboratories that tested the performance of one bat model using the ASTM test method.

  • The Baum Hitting Machine was evaluated by an independent research team hired by Major League Baseball and is considered state-of-the-art for measuring both bat and ball performance. The Baum Hitting Machine is capable of measuring batted-ball velocities for specified combinations of swing and pitch velocities. The Baum Hitting Machine is considered the most sophisticated apparatus available for studying bat-ball impact performance; however, the practicality of this apparatus as a standard test methodology remains to be demonstrated.

  • Several scientific studies have demonstrated that the existing test methodology (ASTM), in its present form, is insufficient for predicting ball performance in game-like conditions. An improved standard test methodology for predicting ball performance is warranted and should be the most timely and cost-effective first step in improving the regulation of bat-ball performance.

  • Numerous factors affect batted-ball velocity, including bat weight and weight distribution. Players can swing bats that are lighter or more "handle heavy" faster than heavier bats. Bat speed was shown to have a stronger correlation with bat moment of inertia than with bat weight. This suggests that it would be more effective to regulate bat inertia than bat weight. The effects of weight and weight distribution on swing mechanics and the ability of a player to alter swing mechanics with practice have not been studied.

    BAT PLAN

    Recommendations of researcher Trey Crisco:

  • Require manufacturers to test bats and balls using specified methodology.

  • Have an independent party collect and analyze the data.

  • Conduct scientific field studies that would examine current batted-ball and swing-speed velocities