Technical - Analytics, tactics, biomechanics, S&C implications

1. Technical Tennis
Doug Eng EdD PhD CSCS
PTR International Master Pro
USPTA Master Pro
617-281-8368 douglas.w.eng@gmail.com

2. What’s Cooking Today
Serving
Recent Tactics & Techniques
Evaluating the Serve – Observational Tennis Serve Analysis (OTSA)
Racquet Head Speed Training – what works and what doesn’t
How Power and Movement is Generated - One Leg Exercises
Comeback of Aerobic Training
Length of Rallies
Player-Specific Training
Stabilization

3. FIRST SERVE PERCENTAGE
• At 2020 Australian Open:
• 12 of 13 women with the highest percentage of 1st serves in
LOST in the first round
• 8 of 12 men with the highest percentage of 1st serves in LOST
in the first round

7. WHAT’S THE HARDEST SERVE TO HIT?
WTA & Juniors: Ad Court Wide Serve
Serve practice 6 to A, 6 to B, 6 to C.
Does that make sense?
Should it be a different number?

8. AD COURT 2nd SERVE – RIGHTY VS RIGHTY
NAME WIDE SERVE T SERVE T+ to FH
% of total % won % of total % won
Djokovic 30.5 61.1 36.9 64.8 +3.7
Federer 48.8 62.2 28.6 59.6 -2.6
Thiem 24.7 59.1 37.2 55.7 +3.4
Medvedev 61.6 55.2 13.0 63.6 +8.4
Wawrinka 61.5 56.6 16.0 55.1 -1.5
Tsitsipas 18.8 52.6 22.7 55.7 +3.1
Kyrgios 54.6 54.0 28.1 59.8 +5.8
Dimitrov 42.7 57.6 14.8 58.1 +0.5
Khachanov 22.7 51.1 24.0 55.2 +4.1
Fognini 30.9 53.4 21.9 55.6 +2.2
Monfils 38.1 56.2 25.1 60.5 +4.3

9. DEUCE COURT 2nd SERVE – RIGHTY VS RIGHTY
NAME T SERVE WIDE SERVE Wide+ to FH
% of total % won % of total % won
Djokovic 37.9 60.2 38.4 61.8 +1.6
Federer 48.8 60.3 27.0 64.4 +4.1
Thiem 50.6 58.4 28.1 59.5 +1.1
Medvedev 42.3 57.4 33.8 65.0 +7.6
Wawrinka 52.8 57.5 26.3 57.0 -0.5
Tsitsipas 30.0 56.2 19.1 55.0 -1.2
Kyrgios 53.0 62.9 32.2 63.9 +1.0
Dimitrov 57.2 56.8 14.1 63.6 +6.8
Khachanov 50.7 56.6 9.0 65.4 +8.8
Fognini 51.9 51.3 18.4 60.3 +9.0
Monfils 44.2 54.9 32.9 59.3 +4.4

10. MOST DIFFICULT SERVE+ONE?
Deuce Court Wide Serve + Return to Backhand + Backhand Crosscourt
Most juniors and club player can’t
get the backhand wide enough and
end up neutral rallying.
Need to practice, one reason to teach the slice

11. Observational Tennis Serve Analysis (OTSA)
Myers, Kibler et al (2017)
Biomechanics
9 Nodes for analysis
For assessment of injuries
For biomechanical efficiency
WHO: everyone!!
NOTE: does not cover grip, rhythm or backswing path behind the back

12. Node 1: Feet
Good: Back foot stays in front of front foot Bad: Back foot stays behind front foot

13. Node 2: Knees
Both knees to bend greater than 15° Bad: Both knees bend less than or equal to 15°

14. Node 3: Counterhip Rotation
Good: The back hip is rotating away from net Bad: The back hip is not rotating away from net

15. Node 4: Posterior hip tilt
Good: Back hip is lowered Bad: Back hip is not lowered

16. Node 5: Hip Lean
Good: Front hip is not leaning forward Bad: Front hip is leaning forward

17. Node 6: X-Angle = between shoulders & hips
≈ equal to 30° Bad: x-angle < 30° Bad: x-angle > 30°

18. Node 7: Trunk
Good: Trunk rotation - vertical axis Bad: No trunk rotation, lateral trunk
bending only
Bad: lumbar hyperextension
Other Bads: hyperrotation, or hyporotation

19. Node 8: Arm
Good: Shoulder in line with the
scapular plane
Bad: Hypercocking – shoulder
behind scapular plane
Bad: Hypococking – shoulder in
front of scapular plane

20. Node 9: Composite Motion of Kinetic Chain
Good: Use knee flexion and back leg drive to maximize ground
reaction forces that push the body upward from the cocking
position into ball impact
Bad: Use trunk muscles to pull the trunk and arm from cocking
into ball impact

21. Other Keys of Serving
• Maximize Early Cocking (Loading)
• Maximize Late Cocking (hyperangulation, elbow valgus, maximal
elbow flexion=MEF)

22. Racquet Head Drops

23. Racquet Head Speed – what works?
• No study shows benefits of racquet speed drills – with same weighted
racquets
• Overweight Racquets ca 150% and 200% were not shown beneficial.
• Too much weight à injuries
• Contrast Training: Baseball underweight and overweight balls ca -12%
to +20% à 2-4%
• Complex Training = Strength + Plyometric, (runners study)
• Plyometric Training – (studies with throwing/shoulder)

24. Racquet Head Speed Recommendations
Strengthening + Plyometric Training (SSC, PAP)
Contrast Training
Technique
Stabilization Training (Efficiency)

25. Why One Leg Training?
• Many athletes have a stronger side
• Symmetry à faster, asymmetry à slower
• Trains balance and stabilizers
• Less loading or weights needed, less strain
• Serving – pushing
• Recovery Steps - long distances require wider outside foot to push back in
• Stepping Forward – aggressive balls
• Volleys
• Split and First 2-3 Steps
Can be 1 or 2 leg countermovement
1 leg for explosive first step

26. One Leg Movement Situations
• One-Handed Backhand Recovery
• Serve + Offensive Forehand
• Moguls – Defensive Forehands (Reverse)
• Pivot Moves – Offensive Forehand but recovery to baseline
• Hop Step – Offensive Forehand from center or ad court with movement to net
• Approach and Volley
• Suarez-Navarro – Keys 1:25-2:30
• Nadal – Kachanov 3:09-4:09
• Nadal – Thiem 0:00-1:27
• Nishikori – Cilic 2:50-3:40
• Pliskova – S. Williams 1:40-2:05

27. Rafael Nadal Serve + One

28. Stan Wawrinka BHs + Mogul

29. Stefanos Tsitsipas Serve + One

30. Julia Goerges Serve + One

31. Julia Goerges Forehand Movement

32. Single Leg Training
Prerequisite – lunges, 2 leg squats, 2 leg plyometrics
• 1 leg Bulgarian Deadlift
• 1 leg Romanian Deadlift with Arm Extended/Cable Pull
• Lunges and Slides
• Lateral Bounds
• Serve on Back Leg
• Vertical Hop and Lateral Bound
• Lateral Hop and Lateral Bound
• Lateral Hop, Lateral Bound, and Sprint

33. Single Leg Bulgarian Deadlift (Split Squat)

34. Reaching DB SL Romanian Deadlift

35. SL Lateral Slide on Slide Board

36. SL Negative Squat

37. Lateral Bounds

38. Inclined Throw with Reach Down

39. Serve on Back Leg

40. Lateral Hop, Lateral Bound and Stroke

41. Lateral Bounds with Stimulus and
Stroke

42. SL Depth Jump

43. Comeback of Aerobic Training
Rally Percentage
Length of Rallies
0-4 70%
5-8 20%
9+ 10%
A. Is this true?
B. How much is serving a factor?

44. Answers
A. No
B. Serving is factor with big serves. Most players win less than 50% of
second serves.

45. What if I don’t have a big serve?
• Train inside-out forehand if backhand is not a weapon
• Train secondary offense – angles, drops, going to net
• Train to run à neutral rallies

46. A B C D
A B C D
Nadal 54% Djokovic 42%

47. Baseline Practice Time?
How should we practice from the baseline?
Where does a player spend the most time?
Where are they most effective?
Least effective?

50. Frequency of Forehands
45.00
50.00
55.00
60.00
65.00
70.00
75.00
-2.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00
Forehand/Backhand Velocity Difference vs % Forehands
Forehand– Backhand Velocity Difference (mph)
%Forehands
Wozniacki
Kerber
Halep
Pliskova
S. Williams
V. Williams
Nadal
Djokovic
Wawrinka
Nishikori
Monfils Keys
Murray
Vinci
Tsonga
Sock
Del Potro

51. Length of Rallies 10+
Murray 16.2%
Nadal 15.4%
Del Potro 15.4%
Djokovic 12.3%
Wawrinka 12.2%
Isner 5.7%
Karlovic 2.4%
Del Potro - Ferrer 23.7%
Monfils – Baghdatis 23.7%
Djokovic – Youzhny 23.7%
Raonic-Brown 1.1%
Karlovic-Young 0.9%
Wozniacki 20.6%
Halep 17.4%
Vinci 15.2%
Kerber 14.0%
S. Williams 7.8%
Keys 5.8%
Wozniacki-Niculescu 43.7%
Keys-Osaka 1.9%

52. Who wins longer rallies?
59.84
50.8151.83
53.72
56.64
44.78
58.68
52.8352.63
63.96
50.00
48.00
50.66
43.24
60.61
48.70
46.30
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
0.00 5.00 10.00 15.00 20.00 25.00
% Rallies Won
Djokovic
Nadal
Nishikori
Tsonga
Del Potro
Sock
Monfils
Wawrinka
Keys
Kerber
Vinci
V. Williams
S. Williams
Pliskova
Halep
Wozniacki

53. Two Extremes of Play
• Big serve produce numbers like 75%, 20%, <5%.
• Relative lesser serves + good returns produce numbers like 60%, 25% 15%.
• Final Factor: Surface Speeds, Temperature
What happens when Isner or Karlovic play?
9+ rallies = 1-2%
What happens when Djokovic-Murray or Kerber-Wozniacki play?
9+ rallies – 25-40+%
Most people are between. Serena Williams and Roger Federer tend to play 7-8% of rallies
under 9 shots. Djokovic and Kerber tend to play above 15% (reported as 19%) over 9 shots.

54. Work:Rest Ratios
• Points under 10 sec
For Big Servers can be 98% of the game
Essentially Work:Rest ratio of 1:3 to 1:10 is 98% of the game
Case 1: When big server meets weak returner (relative)
Case 2: Mismatch opponents
Case 3: Fast surface, fairly good serves
• Points over 15 sec
Can be 20-40% of the game
Essentially Work:Rest ratio of 2:3 is 20-40% of the game
Case 1: When returns can almost equalize and both players are movers
Case 2: Slow surfaces, neither player has really big serve
Case 3: When players are very well matched.
Length of rallies increase with rounds in tournaments

55. Research Point Lengths on Surfaces
Skorodumova & Baranov (2020)

56. What is correlated with rankings?
• Effectiveness of Serve, Return
• Girard & Millet (2009) – Speed, Vertical Jump, Dominant-Side
Strength
• Smekal (2000) - Field Test Hitting
• Ferrauti (2011) – HTTT (Hit and Turn Tennis Test)
• Brechbuhl (2018) – TEST (Test to Exhaustion Specific to Tennis)
What separated women from girls was backhand power and Tennis-Specific and
RSA endurance.

57. Advantages of Aerobic Training
• Need to train tennis-specific endurance and repeated sprint ability.
• Quality shot-making is longer. Players can stay error-free in longer
matches.
• Players can go deeper into tournaments.
• Longer rallies are necessary for some players and some surfaces.
• Against equal opponents, usually 15% of rallies are 10+ shots.

58. Implications
Should it be groundstrokes only?
Physically stronger runners have lower VO2max but run faster
Strengthening Programs
Repeated Sprints, HIIT, Fartleks
Who uses more energy? Offensive players have shorter points but use more
energy (more than counterattackers). So attackers need more
anerobic/power training.

59. Stabilization
• Consistency of movement, hitting stance, recovery
• Consistency of shot-making
• Lack of stabilization à errors, cannot maintain stroke integrity or move effectively to and
from ball
• Simplest drills
• Federer Volley Drill
• Wrist extension for forehand grip – use racquet on net, or hand on wall
• Perturbations – with bands or taps
• Core training – planks, Russian Twists
• Hips/Glutes – lateral band walks, 45 degree band walks
• Balance exercises – 1 leg star drill
• Swiss Ball -
• Medicine Ball