Doctored baseball bats: Digital imaging treats a real corker

June 9, 2003

Digital imaging modalities may play a pivotal role in the latest incident of corked baseball bats.Chicago Cubs star Sammy Sosa was ejected in the first inning of a June 3 night game between the Cubs and the Tampa Bay Devil Rays after umpires found cork

Digital imaging modalities may play a pivotal role in the latest incident of corked baseball bats.

Chicago Cubs star Sammy Sosa was ejected in the first inning of a June 3 night game between the Cubs and the Tampa Bay Devil Rays after umpires found cork in the bat he broke on a routine groundout.

Altering bats with cork or any foreign substance is against the rules of baseball. Hollowing the business end of a bat and filling the core with cork lightens the weight by an ounce or two and is believed to help players hit the ball farther. Following the Sosa incident, baseball officials confiscated a 76 or more bats for closer inspection.

Although the illegal practice is thought to be widespread in baseball, no bat inspection mechanism has ever been established. But history shows that medical x-rays are probably the best imaging tools for nondestructive tests of baseball bats.

In 1987, following a similar corking incident, the baseball commissioner's office asked experts in nondestructive evaluation at the National Institute of Standards and Technology in Boulder, CO, to do a quick study of ways to detect illegal cork or rubber cores bored into the heads of bats.

With four bats (two normal and two with cork cores about two pencil widths in diameter) supplied by Major League Baseball, the NIST team assessed a variety of approaches, including ultrasound and several types of x-ray devices, including CT. Two of the bats - one "loaded" and the other not - were even taken to Boulder Memorial Hospital for diagnostic study, to be viewed from several carefully determined perspectives.

Cross-sectional CT scans clearly showed the corked bore holes in the two loaded bats. Likewise, standard medical x-rays taken along the length of the bat revealed the contrast in density between the pencil-like cork core and surrounding wood in the barrel.

Measurements made with ultrasound were deemed less definitive, and the data took longer to collect and interpret. Differences in grain patterns made it difficult to find unequivocal signatures in data gathered from doctored bats.

The NIST team determined x-rays were the quickest and most practical option - a reasonable choice since most Major League parks are equipped with x-ray machines for diagnosing player injuries.