Of all the things players ask our AI coach, spin comes up the most. Since March there have been around 100 questions about topspin, spin generation and grips, from 59 different players — more than any other technique topic. Nine in ten were follow-ups: players asking again, digging deeper, after the first answer. “Why is my spin generation score 30?” is one of the most-tapped questions in the whole app.

It is also where amateur forehands score lowest. Spin generation is consistently the weakest component across the platform: 87% of the forehands we have analysed scored under 60 out of 100 on it. More concretely, on 36% of 8,011 forehands, the racket was not travelling upward through contact at all — a flat or even downward swing path — and for 38% of players that was true of most of their forehands.

The good news: topspin is not a talent. It is geometry, and geometry can be learned.

What Actually Creates Topspin

Topspin comes from the racket brushing up the back of the ball at contact. Three things control how much you get:

  • Swing path. The racket needs to be travelling upward as well as forward through contact — a low-to-high path. The steeper the path, the more spin.
  • Racket head speed. More speed means more brushing per hit. Spin and pace are not opposites; a fast, upward swing gives you both.
  • Racket face angle. The face should be roughly vertical at contact. Too open and the ball sails; too closed and it dives into the net.

Notice what is not on the list: rolling your wrist over the ball. That is the most common myth about topspin. The wrist turns over after contact as a natural result of the swing, not as the thing that creates spin.

Do I Need to Change My Grip?

This is the single most common follow-up we see. Players with an eastern grip ask whether they have to switch to semi-western; players asking how Federer and Dimitrov get the racket face pointing down ask whether it is the grip.

The honest answer: grip makes topspin easier, but it does not create it.

  • Eastern: great for flatter, penetrating drives and low balls. You can absolutely hit heavy topspin with it, but you need a steeper swing path to do so, and high balls are harder to control.
  • Semi-western: the most common modern grip. It closes the racket face slightly and makes a low-to-high path feel natural. The best all-round choice for most club players.
  • Western: maximum spin and great on high balls, but harder on low balls and slices.

If your swing path is flat, changing grip will not fix it — you will just hit flat with a different grip. Fix the path first. If you are still struggling with high, spinny balls after that, a move from eastern towards semi-western is a sensible next step.

The Low-to-High Swing — Without Hitting Lobs

The worry players raise most often when they try to swing low to high: “Won't that just make the ball go up?” It does if the racket face opens. The trick is that the face stays vertical while the path goes up — the upward motion turns into spin rather than height.

Start with the racket head dropping below the ball before you swing forward. From there, swing up and out towards your target, finishing high over your opposite shoulder. Keep a relaxed grip — around three or four out of ten. A tight grip slows the racket and kills spin.

Drills to Build More Spin

1. Mini-tennis with a steep finish

Rally from the service lines and exaggerate the brush — finish with the racket pointing at the sky. At low speed you can feel the strings grabbing the ball, which is impossible to feel at full pace.

2. Hit over a higher target

Imagine a second net a metre above the real one, or rally over a rope or cones on a stand. Getting the ball high over the net and still landing it in the court is only possible with topspin.

3. Drop-feed and brush

Drop a ball beside you and, after the bounce, brush up the back of it so it climbs and dips. The goal is a ball that arcs, not one that travels flat.

4. Shadow swings in front of a mirror or camera

Check that the racket head drops below hand height before the forward swing begins. You can film shadow swings and get them analysed with no ball at all — swing path is perfectly readable without one.

Common Spin Mistakes

Wrapping the wrist over the ball. Flicking the wrist over at contact tends to close the face and pull the ball into the net. Let the forearm turn over naturally on the follow-through.

Slowing down to “guide” the ball. Topspin needs speed. Decelerating to place the ball takes away the brush, and the ball sits up short.

Starting the swing from too high. If the racket never drops below the ball, there is no low-to-high path to work with, whatever your grip. This is the most common cause of the flat swing paths we measure.

Standing up through the shot. Pushing up with the legs helps lift the racket through the ball. Players who stay stiff-legged often have to compensate with the arm.

How to Track It

On an OnCourtAI forehand analysis, spin generation is measured from your swing itself: how far the racket travels upward through contact, the angle of the path, and racket speed. The target is at least 10 cm of upward racket travel through the hitting zone. Re-film every couple of weeks and you will see whether the path is changing before you can reliably feel it.

If spin is your weakest score, it is a natural first target for a training plan — though it is also one of the harder faults to self-correct, because it means rebuilding the shape of the swing rather than tweaking a detail. Be patient with it.

The Short Version

Topspin comes from an upward swing path, racket speed and a vertical racket face — not from rolling your wrist. Grip can help but will not fix a flat path on its own. Swing low to high, stay relaxed, finish high, and check the result on video.