Is there a difference with the exit velocity of a baseball coming off a flexible or stiff handled aluminum bat?

Dan McKinneyHHP 364

“Some marketing materials say that handle flex improves performance because the "whip action" allows the bat to uncoil and release energy stored during the swing and increases the bat speed at the moment of impact” (Russell, 2007).

“Marketing materials for stiff handled bats claim that stiffer handles allow the trampoline effect in the barrel to be more effective thus improving batted-ball speed” (Russell,2007).

Easton Claims: “It’s trying to improve the way the handles of its bats flex to increase the

size of the sweet spot—the area on the barrel that delivers the most power—so hitters can rap singles and doubles even if they don’t make solid contact” (Greene, 2004).

Louisville Slugger Claims: “Louisville Slugger’s 2009 line is built with stiffer handles and larger

sweet spots in mind. The TPX material says that a stiff handle creates more barrel flex, thus increasing the “trampoline effect” and creating more energy transfer” (Conrad, 2008).

Theories

Handles

VIDEO!http://www.bing.com/videos/watch/video/flexible-handled-baseball-bats/a451f321d19ee1ce2e7ba451f321d19ee1ce2e7b-320627409871?q=flexible%20baseball%20bats&FROM=LKVR5&GT1=LKVR5&FORM=LKVR

Velocity: The rate of speed calculated in Miles Per Hour.

Coefficient of Restitution/Trampoline Effect: The coefficient of restitution is a measure of the elasticity of the collision between ball and bat. Elasticity is a measure of how much bounce there is, or in other words, how much of the kinetic energy of the colliding objects before the collision remains as kinetic energy of the objects after the collision. Louisville Slugger Strategy

Whipping Action: Handle flex allows energy stored in the whip action during the swing to be released at impact in order to provide a greater batted-ball speed. Easton Strategy

Hitting: The sequential unlocking of body parts to maximize bat speed at the point of contact.

Operational Definitions

Ha: The most flexible handled bat (65), will create the highest exit velocity of a batted ball off of a stationary hitting tee!

Ho: There is no significant difference of the exit velocity from different flexible handled bats.

Theoretical Hypothesis

Flexible rating of 3 different Easton Aluminum Collegiate Baseball Bats

The flexibility of bat handles range from 65-100. 100= Stiffest handle 65= Maximum flexibility Test was administered using a 65, 90, and 100

flexible handled ratingDependent Variable

Exit velocity speed of a baseball off of a stationary hitting tee

5 swings per participant with each bat (65, 90, 100)

8 total participants 120 total swings

Independent Variable

Participants

8 MSU-Billings University Baseball Players

College aged Freshman-Seniors

18-24 years old

Randomly Assigned

Trained Collegiate Baseball Athletes

Methods

Apparatus/Materials

Stalker Radar Gun- Used to see velocity/speed of the baseball

5 Wilson A1001-Red Cushioned Cork Center: Premium Leather (Brand New Pearls)

ATEC Tee- Standardized and Stationary

Batting Cage/Net- Located in Lower Gym: MSU-Billings Campus

8 Participants

Instruments Continued…… Easton Aluminum Bats Model-Length-Ounces-Barrel Diameter-Flex

Yellow BSV2 33 in 30 oz. 2 5/8 in

Red BZN1 33 in 30 oz. 2 5/8 in

Green BV2 33 in 30 oz. 2 5/8 in

Yellow: Flex- 65 Flexible Handle Rating

Red :Flex- 90 Flexible Handle Rating

Green: Flex- 100 Flexible Handle Rating

ProceduresParticipant- Parallel to the tee and perpendicular to the net.http://www.bing.com/videos/watch/video/baseball-hitting-instructional-videos-tee-drill/6d2a55979e1869998a216d2a55979e1869998a21-309014495480?q=baseball%20tee&FROM=LKVR5&GT1=LKVR5&FORM=LKVR34

Procedures Continued…. Participants randomly selected. 8 total

participants

Tee placed in front of net

Each participant hit 5 Pearls with each bat

KEY/Instruction: Hit the ball as hard as possible directly into the net and directly at the radar gun

The exit velocity of the baseball was recorded after each swing in miles per hour.

True Experimental Design-Groups were randomly formed, and all subjects were equivalent at the beginning of the research.

Randomized Groups

R T O

ANOVA- Analysis of Variance: Test that allows the evaluation of the null hypothesis between two or more group means.

Design

Data

1 2 3 4 5 6 7 80

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20

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80

90

100

yellowgreenred

Subjects

Exit Velocity

1 2 3 4 5 6 7 80

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20

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90

100

yellowgreenred

Subjects

Exit Velocity

Yellow Bat (65 Flex) Mean: 84.1 MPH

Red Bat (90 Flex) Mean: 84.4 MPH

Green Bat (100 Flex) Mean: 85.4 MPH

F Value= 0.15 P Value=0.86 DF (Degree of Freedom) between groups=2 Error= 14 Critical Value=3.74

No Significant Difference!

86% Chance

Ultimately have to Accept Null Hypothesis◦ .15<3.74 Critical F Value

◦ Pg-405: Statistical Tables

Results

History-Fatigue of Participants

Health of each bat- Dents and overuse

Health of Athletes- Rehab?

Expectations of Athlete/Researcher

Threats to Validity

Money Talks- Maybe it is the operator and not the tool!

Thesis Ideas

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