Friday, March 11, 2011

Off the Backboard Shots Better Bet

The Physics of Bank Shots
Released: 3/10/2011 3:45 PM EST
Source: North Carolina State University

New research by engineers at North Carolina State University show that you had a better chance of scoring that particular game-winning bucket with a bank shot than with a direct shot.

After simulating one million shots with a computer, the NC State researchers show that the bank shot can be 20 percent more effective when shooting at many angles up to a distance of about 12 feet from the basket. Bank shots are also more effective from the “wing” areas between the three-point line and the free-throw lane. However, straight-on shots – those corresponding to the area around the free-throw line – from further than 12 feet are not as well suited for bank shots.

The researchers also found the optimal points where the simulated made baskets were aimed. The results show the optimal aim points make a “V” shape near the top center of the backboard’s “square,” which is actually a 24-inch by 18-inch rectangle which surrounds the rim. Away from the free-throw lane, these aim points were higher on the backboard and thus further from the rim. From closer to the free-throw lane, the aim points were lower on the backboard and closer to the rim.

The researchers also discovered that if you imagine a vertical line 3.327 inches behind the backboard and found where it crossed the aim point on the “V” shape on the backboard, you’d find the optimal spot to bank the basketball to score a basket.
“Basketball players can’t take a slide rule out on the court, but our study suggests that a few intuitive assumptions about bank shots are true,” says Dr. Larry Silverberg, professor of mechanical and aerospace engineering at NC State and the lead author of a paper describing the research. “They can be more effective than direct shots, especially from certain areas of the court – and we show which areas on the court and where the ball needs to hit the backboard.”

The researchers made a few assumptions while conducting the study. They used a men’s basketball, which is slightly bigger and heavier than a women’s basketball; launched the simulated shots from 6, 7, and 8 feet above the ground; and imparted 3 hertz of backspin – which means three revolutions per second – on the shots. The latter variable was shown in previous research to be optimal for successfully converting a free throw.

Tuesday, March 1, 2011

For Hitters on Deck, Warm-Up Devices Don't Increase Bat Speed


Player Preference Should Determine Warm-Up Routine, Reports The Journal of Strength and Conditioning Research

Donuts, bat wraps, weighted gloves…a wide array of devices are available to help baseball players warm up while waiting to go to bat. But a new study finds that none of ten commonly used warm-up devices has a significant effect on bat speed, reports the February issue of The Journal of Strength and Conditioning Research, official research journal of the National Strength and Conditioning Association.

"Furthermore, heavier warm-up devices did not provide greater bat velocity than the 'standard' bat or lighter devices," according to the new study, led by David J. Szymanski, PhD, CSCS*D, RSCC*D, of Louisiana Tech University, Ruston. They believe their results, combined with previous studies, have implications for recommended warm-up routines for batters in the on-deck circle.

Ten Different Warm-Up Devices Show No Difference in Bat Speed

In the study, 22 Division I college baseball players were tested using various devices designed for use in warming-up before batting. The devices ranged from a simple "donut ring," to weighted bat wraps and gloves, to special warm-up bats. The weight of the warm-up devices ranged from 22 to 96 ounces.

At each testing session, the players took three practice swings, as hard as possible, using one of the ten devices. Then, using a standard game bat (33 inches, 30 ounces), they hit a baseball off a tee, attempting to generate maximum bat velocity. A special device was used to measure the velocity of the bat head to see if any of the different warm-ups led to a significant change in bat speed.

Bat speed is thought to be an important component of hitting performance. "The idea is that swinging a heavy warm-up device in the on-deck circle will increase players’ bat velocity with their game bat when attempting to hit the baseball during an at-bat," Dr. Szymanski and co-authors explain. "If bat velocity is increased, this will allow the exit velocity of the batted ball to be greater, resulting in the baseball being hit farther."

In the study, however, none of the ten warm-up devices led to a significant increase (or decrease) in average bat velocity. Bat speed was no different when the players warmed up using heavier versus lighter devices, or with their usual game bat alone.
From Little League to the Big Leagues, batters in the on-deck circle use a variety of weighted devices to warm up for their turn at bat. Some previous studies have suggested that warming up with a heavier bat may lead to perceptual distortion, or a "kinesthetic aftereffect." Warming up with a weighted bat may make the standard bat feel lighter, providing the player with a psychological advantage.

However, the new report finds no evidence that any type of warm-up device affects objectively-measured bat velocity. "This study suggests that Division I intercollegiate players interested in having the highest bat velocity during a game at-bat can use any of the ten implements tested," Dr. Szymanski and co-authors write.
They note that their result differs from some previous baseball research—including a study by DeRenne and colleagues, which found that warming up with a weighted bat of plus or minus twelve percent (4 ounces) of game bat weight produced the greatest bat velocity (in high school players). Other studies have suggested that using a device that adds weight to the top of the bat, such as a donut or wrap, may actually slow bat speed. Dr. Szymanski comments, "Thus we'd suggest that, if players use a warm-up device, they should follow the recommendations of DeRenne and colleagues and use a weight within twelve percent of their standard game bat, and that the weight should be evenly distributed."