Nondestructive Testing Detects Altered Baseball Bats
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From NDT Technician , Vol. 11, No. 4, pp: 1 –5. Copyright © 2012 The American Society for Nondestructive Testing, Inc. The American Society for Nondestructive Testing www.asnt.org FOCUS Nondestructive Testing Detects Altered Baseball Bats Daniel A. Russell* Corked Wood Baseball Bats The prevalence of corked bats in X-rays and CT scans. Pete Rose Major League Baseball is not known was frequently accused of using The history of the game of baseball because players are caught only corked bats during his 1985 chase is peppered with interesting stories when the doctored bat breaks, of the all-time hits record, but no of attempts to break the rules. revealing the cork interior. For broken bats ever exposed cork. Managers have been caught stealing example, in 1974, New York Several of Rose’s bats from 1985 signs; groundskeepers have altered Yankees’ Graig Nettles shattered his are now in private collections. Cthe playing conditions of the field bat, sending several superballs Recent X-ray scans of two of these to the advantage of the home team; bouncing around home plate. In bats show that they were indeed pitchers have used petroleum jelly, 1987, Houston Astros outfielder corked. 3 mud, emery boards, or thumbtacks Billy Hatcher’s bat broke and one of Following the Sosa corked bat to alter the surface of the baseball; the pieces ended up in the hands of incident in 2003, the Major League and Major League Baseball players Chicago Cubs third baseman Keith Baseball commissioner’s office like Albert Belle, Norm Cash, Graig Moreland, who promptly showed ordered that X-ray scans be taken Nettles, and Sammy Sosa, have used the exposed cork filling to the of the rest of Sosa’s bats, including 1,4 corked bats. nearby umpire. The most recent several that had been sent to the Major League Baseball rules example occurred on June 3, 2003 Baseball Hall of Fame after the dictate that a bat must be made when the bat swung by Chicago 1998 home run record breaking from a solid piece of wood. A Cubs centerfielder Sammy Sosa season. The X-rays of all 76 of corked bat has a hole drilled into shattered and the umpire who Sosa’s other bats came back the barrel that is about 1 in. picked up the barrel fragment saw negative; the bat that broke during (25 mm) in diameter and about the exposed cork filling. the 2003 game was the only one 8-10 in. (0.20-0.25 m) deep. The A physics analysis of the bat-ball found to have been corked. hole is filled with tightly packed collision concludes that corking a Sosa’s 2003 corked bat fragment cork or rubber superballs and bat does not provide any was eventually purchased by Grant capped with a wooden plug sanded performance advantage to a hitter, 2 DePorter, CEO of the Harry Caray and painted to disguise its presence. but cannot determine whether or Restaurant Group, and a doctor not a wood bat has been corked. friend used computed tomography * Graduate Program in Acoustics, 4 The Pennsylvania State University; There are, however, several (CT) to scan the bat. The CT scan 201-D Applied Science Building; University Park, PA 16802; nondestructive methods for images in Fig. 1, clearly show the (814) 865-6365; [email protected]. detecting corked bats. FOCUS continued on page 2. Vol. 11, No. 4 TNT · October 2012 · 1 FOCUS continued from page 1. hole filled with cork as well as the mismatch in the grain between the barrel and the wood plug used to fill the hole. In August of 1987, just weeks before the Billy Hatcher incident, Major League Baseball commissioner Peter Ueberroth had asked experts at the National Institute of Standards and Technology to perform a quick study of several nondestructive methods for detecting the presence of illegal cork in a hollowed out wood bat. 5 The study found that CT scans provided the clearest image quality and were the best at detecting corking. However, the study concluded that standard medical X-ray scans were the quickest and most practical, especially since many professional ball parks have in-house X-ray machines for diagnosing player injuries. Ultrasonic Scanning. The 1987 NIST study also explored ultrasonic tests, but found that it was difficult to conclude (a) (b) Figure 1. Computed tomography (CT) images of corked bat used in 2003 by Sammy Sosa: (a) side view of bat fragment and (b) end view of bat showing wooden plug. Reprinted with permission of Dr. Richard Heller and Harry Caray Restaurant Group. 2 · Vol. 11, No. 4 with certainty whether a specific are possible with a solid wood bat. bats, and X-ray scans would not easily reflected signal was due to the Governing bodies, such as the detect evidence of shaving in a presence of cork or the imperfections Amateur Softball Association or the thin-walled hollow composite bat. in the wood grain. However, a recently United States Specialty Sports Ultrasonic measurement techniques published study used a pair of Association have implemented would seem to be the preferred 100 kHz narrow-band contact performance standards to regulate bat method for detecting alterations in transducers (receiver and source) to performance either by placing an hollow softball bats since ultrasonic measure the signal strength upper limit on the batted-ball speed or sensors are frequently used to measure transmitted through three 4 in. by limiting the coefficient of the thickness of hollow metal, plastic (102 mm) thick blocks of sample restitution between bat and ball. Bat and composite pipes. However, wood: with and without cork filled performance is measured following an knowing the barrel wall thickness holes. 6 The signal transmitted through ASTM test protocol 9 which fires balls would detect modification only if one the hollow block suffered an at approximately 150 mph (240 km/h) knew the original wall thickness and attenuation of 15.2 dB compared to toward a stationary bat and uses manufacturers are unwilling to make the solid block. The corked block measurements of the bat and ball this information publically available. resulted in 9.6 dB of attenuation. speeds before and after the collision Reflections from the air gaps between Clean signals require a layer of liquid to determine the coefficient of the thin layers of a double-walled between the transducer and the bat restitution of the bat. Knowledge of aluminum bat, or from the different barrel surface, something prohibited the inertial properties of the bat layers of composite and resin in by Major League Baseball rules. The allows for calculation of the batted multi-walled composite bats could lead device has not yet been brought to ball speed. Measurement of bat to errors in thickness measurements. market, but the technique shows performance in the laboratory is time The difficulty in detecting illegally promise. intensive and expensive, and requires altered softball bats is exacerbated by Doctored Metal And Composite specialized ball cannons, light gates, the fact that it is possible to improve Softball Bats bat pivot devices, and computer the performance of a composite bat hardware for data collection and without actually changing the The problem of illegally altering wood processing. 10 thickness of the barrel walls. A bats in Major League Baseball is Almost as soon as bat performance currently popular technique for certainly newsworthy when it happens, standards for softball were adopted, improving the performance of a but it does not occur with great players discovered that they could composite bat is to use one of several regularity. The opposite is true in significantly improve the performance accelerated break-in methods. 12 It is amateur slow-pitch softball, where the of a bat by modifying it to increase well known that the performance of illegal modification of bats is much the trampoline effect. So-called bat composite bats improves with use as more prevalent but does not often doctors sprang up around the country, the layers of composite materials make the news. 7 The bats used for offering to cleverly repaint banned gradually delaminate with use and the men’s amateur slow-pitch softball are high-performance bats, add or remove bat wall softens, increasing the manufactured almost exclusively from mass in the barrel or handle of the bat trampoline effect. A quick search of aluminum or composite materials, and to change the swing weight the web will reveal a small industry for the barrels of these bats are hollow. (moment-of-inertia), or the more rolling and pressing bats to accelerate The collision between a softball and a drastic modification of removing the the break-in process. Awareness of hollow bat barrel gives rise to the end-cap and using a lathe to shave the this phenomenon led the Amateur so-called trampoline effect in which the inner wall of the barrel. 11 Governing Softball Association to begin rolling hollow barrel compresses as a spring, bodies have imposed heavy penalties bats prior to certification testing for temporarily storing the energy from and fines against players caught using compliance with their performance the collision and then returning almost illegally altered bats, but the detection standard, and also caused the National all of that energy to the ball as the of altered bats in the field of play has College Athletics Association in 2009 barrel elastically recoils to its original presented a challenge. to ban composite bats from use in shape. 8 Careful design of the barrel While X-ray machines may exist in college baseball after a large number wall thickness and material properties most Major League Baseball stadiums, of certified composite bats were allows the trampoline effect to be they certainly do not exist in a found to exceed performance tuned, maximizing the efficiency of portable form at the thousands of standards when tested following the the bat-ball collision to the extent that amateur softball parks across the College World Series that year.