Wood vs. Non-Wood Bats: Comparing the Performance of Baseball and Softball Bats
With all the recent discussion about the new BBCOR standard for non-wood bats, I have put together some information that I hope people will find useful. The goal is to establish a scientific framework for addressing the issue of bat performance.
Beginning with the 2011 season, the NCAA started using the new BBCOR bat performance standard. The same standard will be adopted by the National Federation of High Schools in 2012. And it is quite likely the various youth bat organizations will adopt a similar standard in the near future. The following are some links related to this new standard.
- Regulating the Performancs of Bats, published in The Hardball Times Annual 2015. This is an layman's article I wrote about bat performance, what it means, how to measure it, and how to regulate it.
- NCAA Baseball This is a link to a video of an ESPN Sport Science episode, which first aired on June 24, 2013. The story is about the reduction in offensive production due to the BBCOR bats, first introduced in 2011, and how the production would be restored by switching to the MLB baseball. The essence of the story is that the "carry" on a flat-seam MLB baseball is considerably better than on a raised-seam NCAA baseball. The data on which the story is based come from the MS Thesis of Jeff Kensrud, "Determining the Aerodynamic Properties of Sports Balls In Situ".
- Comparing the Performance of Baseball Bats : A nontechnical article I wrote for The Baseball Analysts. It appeared on January 18, 2010. This is a reasonable starting point, since it explains what BBCOR actually is and how it is measured.
- NCAA Baseball Bat Standards and 2011 NCAA Baseball Bat Standards are the two sites for all information related to the NCAA and their bat performance standards.
- Reduction in Power, a story written by Lou Pavlovich, Jr. and appearing in the Sept. 3, 2010 edition of Collegiate Baseball. The story is largely the result of Lou's interview with me regarding the new NCAA bat performance standard that will take effect starting in 2011. The article is very well written and mostly accurate.
- Making Metal Bats Play Like Wood: An informative article written by Pat Borzi and published in the New York Times, June 18, 2011.
- Sport Science: Bat Performance: An episode of ESPN Sport Science that initially aired on April 14, 2011. It is reasonably informative, mostly correct, and quite glitzy.
- Aluminum Bats, Performance Standards, and College Baseball Trends: An article written by Dr. Dan Russell about the effect of the new BBCOR on statistical trends in NCAA baseball.
The following are some papers published in the scientific literature that address the issue of bat performance.
- Evaluating Baseball Bat Performance, a technical peer-reviewed paper published in Sports Engineering in 2001 by Prof. Lloyd Smith. This paper is the first to take make a critical scientific evaluation of the various metrics of bat performance.
- Characterizing the Performance of Baseball Bats, a technical peer-reviewed paper published in the February 2003 issue of American Journal of Physics. In this paper I present the issues involved with characterizing the peformance of bats from a physics point of view. I give precise definitions for some commonly used terms, such as COR, BPF, and BESR. I describe laboratory measurements one could to do decide if an aluminum bat outperforms a wood bat. A new method for characterizing bat performance is proposed and compared with existing methods used by the NCAA, ASA, ASTM, etc.
- Progress in Measuring the Performance of Baseball and Softball Bats. This paper is written by Prof. Lloyd Smith, director of the Sports Sciences Laboratory at Washington State University and inventor of the LVS machine that is now an industry standard for measuring bat performance. The paper, published in the Journal of Sports Technology (vol 1, pp. 291-299, 2009), describes the current state of the art.
- Reducing the Effect of the Ball on Bat Performance Measurements, by Alan M. Nathan, Lloyd V. Smith, and Warren L. Faber, Sports Technology (accepted for publication, June 2011). This paper describes a new procedure for normalizing the performance of the bat to the COR and dynamic stiffness of the ball. The method is shown to be superior to another often-used technique.
- Performance Versus Moment of Inertia of Sporting Instruments, by Rod Cross and Alan M. Nathan, Sports Technology 2, 7-15 (2009). This paper shows that the performance of a bat depends much more on its moment of inertia than it does on its mass. Moreover, it shows that for bats in use by NCAA players, the performance depends far more on the BBCOR than it does on either the mass or the moment of inertia.
- A Comparative Study of Baseball Bat Performance, by Alan M. Nathan, J. J. Crisco, R. M. Greenwald, D. A. Russell, and Lloyd V. Smith, Sports Engineering 13, 153-162 (2011). This paper is the only known study of a comparison between field and laboratory performance. The importance of the BBCOR for determining field performance is established experimentally. A formula is derived relating a batter's swing speed to the inertial properties of the bat.
The following are some additional useful links.
- Baseball Research Center, the bat and ball testing facility at University of Massachusetts/Lowell that was used to certify baseball bats for the NCAA prior to 2011. The facility is directed by Professor Jim Sherwood.
- Sports Sciences Laboratory, the bat and ball testing facility at Washington State University that is used to certify softball bats for the Amateur Softball Association and baseball bats for the NCAA. The facility is directed by Professor Lloyd Smith. There are some great YouTube videos from the lab.
- Professor Dan Russell, my friend and colleague from Penn State Univeristy, who has written extensively on bat performance.
- How a Baseball is Made: A YouTube video.
