Objectives/Goals
The two largest manufacturers of baseballs certified
for use in Little League Baseball competition are the Rawlings Sporting Goods
Company and Diamond Sports Company, Inc.
Since Rawlings is the sole supplier to
Major League Baseball, and the MLB balls had quality control issues noted in
recent reports, it was proposed to see if they also existed at the Little
League level, and to compare the consistency of the Rawlings and Diamond balls,
with the hypothesis of: Little League baseballs made by Rawlings are not as
consistent in their performance, size and weight as those made by Diamond.
Methods/Materials
Materials: 1 dozen each of Rawlings and Diamond
brand Little League Competition Grade Baseballs. Testing performed included:
1) Measurements, using a digital scale and a
flexible measuring tape, of uniformity in weight and circumference against the
specifications of 5.0 to 5.25 oz. and 9.0 to 9.25 inches, respectively.
(English units of measure were used, as that is what is used in the baseball
specifications).
2) Bounce tests for liveliness, where a dozen
samples of each brand of ball were dropped from a height of 72inches, recording
the maximum rebound height of the balls on the 1st bounce, giving a rebound
percentage comparable to that done in the Major League ball testing. Two rounds
of bounce tests were performed and recorded with both digital video and still
cameras.
3) Visual inspections of both the exterior of all
the samples and a cross section of a randomly chosen ball from each brand to
check how each is constructed.
Results
Findings showed that while the Rawlings balls did
have some quality control issues in the areas of weight and size, their
performance was consistent within the brand.
The Rawlings balls' rebound
percentage was less than the Diamond balls', but it was noted that different,
softer materials were used in the Rawlings ball construction when compared to
the Diamond ball construction.
Conclusions/Discussion
Rawlings' quality control IS lacking somewhat as
evidenced by the larger size and weight differences when compared to the
Diamond balls.
But it is the difference in ball construction
between the Diamond and Rawlings Competition-Grade balls that most likely
explains the difference in the performance test results, NOT quality control. Thus,
the results both partially prove and disprove the hypothesis.
Project
Summary
An examination of how quality control and material
construction affects the performance of Little League baseballs.
Christopher S. Avery
0 comments:
Post a Comment