A great serve is the ultimate weapon in tennis – and the hardest stroke to master. The good news? After analysing 200 players in the last 3 months alone, OnCourtAI can now tell you with 100% certainty what’s really stopping your serve from reaching the next level.
Spoiler: it’s almost certainly one (or all) of these three things.
The 3 Serve Killers Affecting 75% of Players
Our AI processes up to 50 unique metrics per serve – from toss height and contact point to balance and weight transfer. The data is crystal clear:
- 75% of players have a poor Trophy Position
- 60% lack sufficient Knee Bend
- 70% make contact too low or too far behind
Fix these three areas and you’ll instantly add power, spin, accuracy – and confidence – overnight.
1. Trophy Position – The Hidden Power Leak
The trophy position is the moment your hitting arm is bent at 90° with the racket pointing upwards, just before the explosive upward swing.
Most players rush it or never reach it properly. Our data shows:
- Average elbow-to-shoulder angle in trophy pose: 112° (should be 90–100°)
- Racket drop depth: only 18cm behind the head (elite players average 32–38cm)
Fix: Pause at trophy position during shadow swings.
2. Knee Bend – Your Free Power Source
Leg drive accounts for up to 54% of serve power. Yet most club players barely bend their knees.
OnCourtAI findings:
- Average knee flexion at trophy: only 118° (pros average 135–145°)
- Ground force generation: 38% lower than elite players
Fix: Use our “knee bend” metric – aim for 140°+ knee bend and explosive push-off. Players who improve this metric add an average of 9–14 mph to their serve speed.
3. Contact Point – Where Winners Are Made
Contact point is everything on serve. Hit too low = weak slice. Too far behind = loss of power.
Our AI measures contact relative to your maximum reach:
- Average contact height: 82% of max reach (pros hit at 94–98%)
- Lateral position: 22cm from centre line (pros <12cm)
Fix: OnCourtAI shows you where you need to improve using real metrics. One month of focused practice moves most players into serving more consistently and stronger.
Why OnCourtAI Serve Analysis Is Different
Traditional coaching gives you one or two tips per lesson. OnCourtAI gives you up to 50 data-driven insights per serve, including:
- Toss consistency (placement & height)
- Racket head speed at contact
- Pronation timing and angle
- Shoulder rotation
- …and 44 more
Players using our serve analysis improve their average serve score from 54 to 65 in just 8 weeks.
Ready to Transform Your Serve?
Upload a 30-second video of your serve today and get your full AI breakdown in seconds – including personalised drills to fix your Trophy Position, Knee Bend and Contact Point.