An Examination of the Effects of NCAA Aluminum Bat Restrictions on Offensive Team Performance, 2010--2011

• Activity Number: 539
• Type: Contributed
• Date/Time: Wednesday, August 7, 2013 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics in Sports
• Author(s): Aaron R. Baggett*+ and Grant B. Morgan
• Companies: University of Mary Hardin-Baylor and Baylor University
• Keywords: Baseball ; NCAA ; Multivariate statistics ; Sabermetrics

Abstract

Beginning in the 2011 season, the NCAA issued a mandatory ban on all non-wood baseball bats not conforming to a set of newly adopted performance standards. Prior to 2011, teams and individual players accumulated record offensive statistics, which subsequently resulted in a perceived uneven competitive balance between pitchers and hitters, as well as concerns about player safety. The purpose of the current study is to examine the effects of changes in offensive performance measures, which can potentially be used as an indication of alternative competitive strategies teams might have employed in order to compensate for the reduction in the new bats' recoil efficiency. Computed 95% confidence intervals indicated that NCAA Division I teams hit between 21.0 and 25.0 fewer home runs, executed between 7.7 and 10.8 more sacrifice bunts, and stole between 2.54 and 8.0 fewer bases, on average in 2011 than in 2010. The change in bat regulations from 2010 to 2011 accounted for 67% of the variability in home run, sacrifice bunt, and stolen base differential. The univariate effect size estimates for home runs, sacrifice bunts, and stolen bases in the study were 1.3, .68, and .22, respectively.