Doug Eng EdD PhD

douglasweng@yahoo.com6172818368

Hand-Held Tennis Technology and How It Can Enhance Your

Coaching

AcknowledgementsBesides the usual suspects,

• Paul Robbins, Stats.com LLC• Donny Soh, QLIPP• Rick Gould, TuringSense

• Yuval Bar Yosef, PlaySight • Peter Lyons, Babolat• USTA PD & Sport Science Committee

Technology - How Can it Help?• Measure Physical abilities• Enhance Teaching• Analysis of Tactics (Analytics)• See New Things (we never noticed)• Understand Techniques and Tactics• Revolutionize Learning• Excitement – new twists

Different Technologies Work Together

Smart Phones and Tablets Racquet Sensors Wearable Technology

Analytics Apps Technical Apps Practice Apps

Useful Technology• Easy Learning Curve• Add Value to Lessons/Coaching• Frequent Use• Will Help Student (or Coaches)

What’s in Your Smart Phone?• Magnetometer• Satellite GPS• Gyroscope• Accelerometer• Proximity Sensor• (Barometer, Light Sensor, Heart Rate Monitor)

Racquet SensorsBabolat POPQLIPP SensorSony Smart Tennis SensorZepp Tennis Sensor

Basic Features of All:Identify shot type (Forehand, Backhand, Serve, Volley)Identify racquet head speedQualitative spin identificationStores data

Babolat POP• Price $69 (MSRP $89)• Easy to Set Up• Works with All Racquets• Can Compare with friends• Intrusive wrist band• Misses some shots (misses ~10-20%)• Short battery & bluetooth issues• Misidentifies some shots (~10%, poor wrist placement)• Poo speed accuracy (10-25% off)

QLIPP Sensor• Price $99 (MSRP $129)• Easy to Set Up• Unintrusive Placement on Strings• Works with All Racquets• Video Pairing• Ball & Racquet Speed • Sweet spot• Records almost all shots (~98+%)• Longest Battery and best Bluetooth pairing• Speed Accuracy is good (~10%)• Records Qualitative Spin• Can be tough to remove

Sony Smart Tennis Sensor• Price $165 (MSRP $199)• Can Take a While to Set Up• Unintrusive Placement on Butt• Works with Some Latest Racquet Models (HEAD, Prince, Wilson,

Yonex)• Video Pairing with Data on Video• Ball & Racquet Speed • Graphical Display• Records most shots (~90-95+%)• Short Battery and poor Bluetooth pairing• Speed Accuracy may be best(~5-10%)• Records Qualitative Spin

Zepp Tennis Sensor• Price $99 (MSRP $149)• Needs calibration and set up takes some time• Intrusive Placement on Butt (Flex Mount, Pro Mount)• Works with All Racquets• Ball & Racquet Speed • 3D Serve • Records nearly all shots (~98+%)• Good battery and bluetooth • Speed Accuracy is fair (~10-15%)• Records Qualitative Spin• Can misidentify shot types and spins

QLIPP FEATURES

QLIPP MODE 3: SERVE MODE• Calculates the serve form:

• Ensures there is proper backswing, good

acceleration and follow through

• Calculates the estimated serve speed based a

combination of:

• Racquet head speed

• Racquet acceleration

• Sweet spot

Tactical Analytics • Macro systems

• PlaySight• Hawkeye

• Micro systems• Pro Tracker• Game Changer• Traditional Stats (TennisStats, MyTennisStats)

20

Soccer and Basketball have been using cameras to track performance – like Hawkeye does for the ball

Now we can use the same XYZ data to track tennis players

Hawkeye- acce/decel data

Distance (meters) Meters player traveled during point

Duration (seconds) Time duration of each point

Max Speed (max [meters/second]) Max speed within each point

Average Speed (avg [meters/second])Average Speed during each point

Kinetic Energy (sum[1 kg meter2 / second2])Total Kinetic energy used in each point

Accel/decel loads and numbers based on intensity

Speed and EnergyExample of a player’s movement during

point

**Player tracking graph created for each point

Point start

point end

Physio and Mech load/intensity

Identify high-stress specific movements, match up with video

Assess within-point inefficiencies

Distance = 33.8 metersDuration = 16.04 secondsMax speed = 5.54 m/sKinetic Energy = 2835 JAcceleration Stress = 13.8Deceleration Stress = 7.71Acceleration 1 = 4Acceleration 2 = 1Acceleration 3 = 2Acceleration 4 = 3Deceleration 1 = 4Deceleration 2 = 2Deceleration 3 = 1Deceleration 4 = 2

Play-by-PlayVelocity Graph (meters/second)

The aim of this paper is to discover patterns of player movement and ball striking in tennis using HawkEye data which are indicative of changing the probability of winning a point.

“The Thin Edge of the Wedge” Xinyu Wei1, Patrick Lucey2, Stuart Morgan3, Machar Reid4 and Sridha Sridharan1 : Accurately Predicting Shot Outcomes in Tennis using Style and Context Priors 

Winning Probability

ProTracker$49.99• Traditional Stats• Service, Return, Deciding Shots Placement• Momentum• No Ad

• Not Flexible for Match Length

Game Changer• $24.99• Traditional Stats Specialty Shots• Service, Return, • Deciding Shots Placement• Various Scoring

• Not Flexible for • Match Length

Micro Video Analysis• Low Budget• Smart Phone for Camera and App Software• Comparison Side by Side, Pro Library• Sharing with Students and Community• Storage and Saving Files

Comparison of Video Analysis Apps(all available on iTunes and Google play)

• Multiple tiers for features & storage ($4.99 and up)

• High Speed - good• Good video quality, loss in

upload• Learning Curve - easy• Voice Analysis – excellent,

during video• Import/Export – Easy without

locker, allows from camera roll, youtube, GoPro

• Sharing – Easy, public• Tools – good

• GRADE = A-

• Base Cost=$6.99 (ncludes angle tool) - multiple tiers for storage, can be pricey

• High Speed - good• Good video quality• Learning Curve – moderate• Voice Analysis – good, need

to make stills, key positions are useful

• Import/Export –allows from camera rolls, also Dartfish locker

• Sharing – closed• Tools – excellent, synch wheel

is best

• GRADE = B

• Free - but tiers for comparison & storage

• High Speed – best built in• Fair video quality• Learning Curve – easy• Voice Analysis – during video• Import/Export – easy, camera

roll• Sharing – easy, public• Tools – fair

• GRADE = B+

COACH’S EYE DARTFISH EXPRESS HUDL

Features & Tools

• Import & Export• Synch Wheel• Tools (angles, distances, arrows, lines, circles)• Titles, comments• Voiceovers

• All apps have basic tools. Angles and measuring are more advanced.

• BASICS TOOLS arrows, lines, circles

Cameras, Tripods & Mounts

Split Screen Comparisons• Before and after correction/cue

• With a touring pro model

• Over time (e.g, 1-2 years)

• Different angles (multiple cameras)

Whiteboard Apps• Scout Free

• Free• No Learning Curve• Hand drawing

• CoachNote• $4.99 ($1.99 Google)• Moderate Learning Curve• Can customize• Can do many sports• Icons – could use better tennis icons

What You Can Use• Racquet Sensor• Video Analysis for Technique• Analytics App• Whiteboard

• Now you are equipped!

Multiple Sensors

05/03/2023 TuringSense Confidential

MODEL EXTENSION (4 SEGMENTS)• FE

45

-40 -20 0 20 40 60 80 100 120 140-160

-140

-120

-100

-80

-60

-40

-20

0

20

X-Forward (cm)

Y-D

own

(cm

)Sagittal plane - Right

Elbow sagittal positionWrist sagittal positionInterface sagittal positionRacket sagittal position

What’s the Future?• More sophisticated analytics tracking• Combined Racquet + Court Sensor• Wearable Technology (multiple sensors for accuracy)• Integrated Tactical/Technical Coaching Systems