Recently, New York City Council moved toward ban on using metal bat in high school baseball games. :-[ Actually, there have been a couple of accidents in which young promising player passed away, due to not enough time for protecting against the batted ball.
I am for using metal bat. Important thing is not to prohibit using metal bat, but control the coefficient of restitution (rebound) and keep time duration to protect his own body.
I try to make sure how long is it necessary for a pitcher to protect against the batted ball. Nicholls R.L., et al introduced that it was approximately 0.4 s, from a unpublished manuscript by Cassidy PE, et al, in their paper (Journal of Applied Biomechanics, 19, 283-294, 2003). But, they did't describe how was it calculated? Does anyone know it or have copies of the Cassidy's paper? I really know it.
Post by Glenn Fleisig, Ph.D. on Mar 22, 2007 8:19:45 GMT -6
I have a copy of the unpublished paper. It does not seem to include any original data collection, but merely made conclusions based upon other studies. If you email me your fax number, I will send it to you. It's about 12 pages.
I am against legislating bans on metal bats by any local, state or federal government. That said, I am an advocate for the return to the use of wood bats both for safety and asthetic reasons. Your concern about the (BESR) Ball Exit Speed Ratio you refer to as rebound is in fact the issue, not the raw material makeup of the bat. While in theory it would probably be possible to make a bat constructed of any number of materials that would have a BESR equal to a wood bat, the fact is aluminum bat companies have found a lucrative niche and are exploiting their marketing skills for financial gain. They are not concerned with your child's safety. BESR is just a minor barrier they have to jump over. There are all sorts of ways to manipulate a metal bat that makes them outperform wood in more ways than one.
Let me suggest you think about what aluminum bats have done to the youth pitcher over the years. With the larger sweet spot, lighter weight and higher BESR, youth pitchers throw much more pitches in one inning to achieve three outs than they ever have. If facing the same team with a wood bat, a pitcher might have a much different and more positive experience.
Post by rgreenwald on Apr 24, 2007 12:49:15 GMT -6
A brief answer to your question about BPF vs BESR - I dont think there is an easy comparison between the two because they measure different things about the bat and a collision with the ball. I havent seen published data relating the two - Jim Sherwood at UMass Lowell might be the best source for this info
ASTM (American Society for Testing and Materials - http://www.astm.org) standards committee F08.26 on baseball and softball equipment has definitions for these terms as defined in various standards. These metrics come from different tests performed on bats, usually using a cannon to fire a ball at a stationary bat. Other test methods have been used with a swinging bat and ball in motion.
3.1.3 ball exit speed ratio (BESR), n—ratio of ball exit speed (vr) to ball inbound speed (vi) plus one-half, as determined by these test methods.
3.1.6 bat performance factor (BPF), n—ratio of BBCOR to ball COR as defined in these test methods. (BBCOR is batted ball coefficient of restitution measured using , and ball COR is ball coefficient of restitution as measured by a standard test for firing a ball at a steel plate - standard F1887)
I couldnt paste the equations into this forum - sorry.
Post by Yungchien "Amiao" Chu on Apr 25, 2007 15:11:14 GMT -6
I personally agree with Dr. Matsuo's opinion about metal bats. Probably I have mentioned in other discussion threads, using wood bats in high school or earlier would kill the development of good player. I succesfully predicted and saw it happend in Taiwan recent years. After four years application of new policy using wood bats in Taiwan, scouts are generally disappointed as they don't find power arms anymore. No, you won't find a Chien-Ming Wang or Chin-Hui Tsao from Taiwan anymore.
The fact is junior national team of Taiwan can compete with Japan when we were using metal bats but not anymore now. Even college players in Taiwan and Japan, who use wood bats, can never outperform American college players in international competitions using wood bats. American players use metal bats in NCAA plays, and shift to wood bats during one or two weeks of practice and easily outperform the Asian players just because they are better hitters. Using wood bats in high school and college do not make better hitters.
High school hitters just can not hit the ball well using wood bats, as it is a high skill owned by professional players. While there are even many excellent players who are good enough to be drafted into pros and will eventually end their career never master the wood bats, how smart the idea of giving younger average kids wood bats could be? They also don't have enough strength to control the wood bats. The result, they can not hit the ball hard, and make easy outs. Finally they all become contact hitters and never develop their swing velocity and power hitting. For only very limited numbers of hitters, they still have the power to hit the ball far, but they only bite the breaking balls as they are not able to hit fastballs due to the heavyness of bats. They will never develop the skill of hitting fastball.
Somebody may say pitchers can throw less pitches and it is healthy to them. No, the number of pitches are regulated by rules and coaches, not the bats. While pitchers can easily make the hitter out, there is generally no motivation for them to improve the ball velocity of sharpness as they don't need them. Instead, a slow and sloppy breakingball will be enough to make the hitters out, much more efficient compared to a sharp or fast pitch, which may be not easy to control by young pitchers. Finally, a lot of sloppy pitchers will occur on the mound.
Moreover, there is one thing that many wood-bat lovers overlooked. When a baseball team change to wood bats, the expense on buying bats will crazily increase. Young players lacking of hitting skills may break the bats more frequently than pros. Many teams may not able to exist anymore due to lack of budget, and many kids lost their chance to play as the family can not support them anymore. It is suspected that the high expenditure of playing baseball have let lots of good athletes, especially African Americans, choose to play basketball instead. And several programs are running to financially increase the participation of baseball for kids in low-income families. We should make baseball a more affordable sports to kids, not making it a sports that only rich guys can play.
I understand that manufacturers will always find some way to improve the bat performance under the restriction of league standards. However, it means the standards need to be changed and improved to maintain the safe play, not changing metal bats to wood bats.