Composite baseball bat

Composite baseball bats, opposed to aluminum or wood baseball bats, incorporate a reinforced carbon fiber polymer, or composite, into the bat's construction. This composite material can make up all or part of the bat. Bats made entirely of this polymer are referred to as composite bats. Bats which only incorporate a portion of polymer (and the rest either wood or an aluminum alloy) are referred to as composite hybrid bats. These composite material provides an advantage over aluminum alloys and wood in durability, weight distribution, improved trampoline effect, and a higher damping rate (to reduce hand sting).

Composite bats can also be constructed to improve their trampoline effect over time. That advantage, namely the improved trampoline effect over a break in period, put the use of composite bats under further NCAA scrutiny during the 2009 NCAA Division I Baseball Tournament. Composite bats, tested after they were already broke in, showed performance standards well beyond the accepted ball exit speed ratio (BESR) Test.

As a result, a new standard, known as the batted-ball coefficient of restitution (BBCOR), was put in place in 2011 which required an accelerated break in period and testing to measure the trampoline effect of composite bats. Since the new restrictions on composite baseball bats NCAA hitting production has been noticeably dampened.

Composite bats have been around as early as the 1980s for use in slow-pitch softball. Most notably, Louisville Slugger developed a slow-pitch bat that was awarded best performance at the 2001 Bat Wars. Miken responded in 2002 by developing their own composite softball bat. Even though composite material has only been historically used in slow-pitch and softball, this technology has emerged in little league, high school and collegiate baseball as early as 2000.

The design of a composite bat depends on which league it is suitable for play. Composite bats are used in a number of different leagues. Most Little League programs have governing rules concerning composite bats. High school (NFHS) and Collegiate play are governed under the BBCOR standards. Metal or composite bats are not allowed in the MLB or its affiliates.

To be suitable for play in BBCOR leagues (NCAA, NFHS, etc.), for example, composite bats must meet certain requirements. Many of these requirements are the same as their aluminum or wood counterparts. For example, the bat's weight to length ratio, known as the drop (length in inches - weight in ounces), must equal negative three. Meaning, a bat with a 33-inch length must weigh 30 ounces. Further, no bat's barrel diameter, at any point, can be greater than 2 5/8 inches. For composite bats there is added scrutiny. Specifically, the rebound rate or trampoline effect, after an accelerated break in period, must stay under certain requirements.

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