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.

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.