bat flexibility- hhp 364
TRANSCRIPT
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>1=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>1=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
10
20
30
40
50
60
70
80
90
100
yellowgreenred
Subjects
Exit Velocity
1 2 3 4 5 6 7 80
10
20
30
40
50
60
70
80
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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