An Overlooked Source of Errors

Have you ever had this experience: the stroke looks right, yet every so often the ball drops into the net or sails long, and you can’t say why.

Many of these unexplained errors trace back to an unstable center of gravity.

The signs are easy to see: you lean and wobble as you play — the body tips back at contact, sways side to side when you move, and bobs up and down when you loop.

Once the weight is off, the contact point drifts and the racket angle changes. Every stroke you make after that is built on a shaky foundation.

Three Dimensions of Stability

To judge whether your weight is stable, look at three directions:

① Side to side (lateral) When you move and rotate, does the weight transfer smoothly between the feet instead of tipping side to side?

② Front to back Does the body tip back when you generate force? Does the weight sit back when you loop?

③ Up and down (vertical) This is the most overlooked dimension, and the most damaging: how much do you rise and fall through the stroke?

Vertical Bounce: The Amateur’s Biggest Hidden Enemy

Why does vertical bounce matter most? Because it directly changes the height at which you strike.

Picture setting up to loop: you sink first, then rise. If you contact while rising, the hit point is higher than you expect; if you contact while sinking, it’s lower. The same stroke, a floating contact point — so the ball floats too.

Worse still, bouncing bleeds your power off in the vertical direction. Part of the force from your legs is spent lifting your body instead of being delivered into the ball.

The core principle: keep your body height as constant as possible through the stroke. The weight can move forward-back and side-to-side, but vertically it should stay level.

Four Typical Causes of Instability

Cause 1: The weight sits too high. Stand straight and your center of gravity rides above your waist. The higher it is, the less stable you are — simple physics. Bending the knees is the first tool for stability.

Cause 2: The weight sits on the heels. With the weight on your heels you sit back — slow to start against a fast ball and prone to tipping back when you hit hard. The right spot is the balls of the feet.

Cause 3: A loose core. The core is the muscle group that stabilizes the torso. Let it go slack and the upper body sways side to side and front to back as you move. Stability is half legs, half core.

Cause 4: The weight doesn’t reset after contact. Finish a stroke with the weight stuck on the side you just loaded and the next ball starts from a crooked position — the more you play, the messier it gets. Between every ball, let the weight come back to the middle.

Stability and Relaxation Are Not in Conflict

Someone will ask: if stability matters, should I stay tense the whole time?

No. Stability comes from structure — bent knees, the core, correct stance — and from control, not from muscular tension.

Tight muscles make you stiff and slow, which makes adjusting the weight harder, not easier. Real stability is relaxed but supported — the body loose, the frame solid, the weight ready to move at any moment.

Training (2–3 Times a Week, About 25 Minutes)

① Half-squat hold (3 minutes) Bend the knees into a half squat with the weight on the balls of your feet, and hold 30 seconds × 4 sets. Feel what low, supported weight is like, and make it muscle memory.

② Book-on-the-head balance (5 minutes) Balance a book (or a light cup) on your head while shadow-swinging or shifting your weight in place. If the book falls, your upper body moved. It’s the most direct feedback drill for your weight.

③ Mirror check (5 minutes) Shadow-swing in front of a mirror and watch only your head height. The goal is a head that moves along an almost straight horizontal line.

④ Single-leg stability (5 minutes) Stand on one foot and swing, 20 seconds each side × 3 sets. This trains the weight’s single-leg support and pays off hugely in step-around and crossover footwork.

⑤ Anti-sway core (7 minutes) Plank 40 sec × 3 | side plank 30 sec each side × 2 | bird dog 10 each side × 3

Four Ways to Self-Check

Check 1 · Head-height line. Record yourself and see whether the top of your head travels roughly on one horizontal line. Big vertical swings mean an unstable weight.

Check 2 · Contact-point consistency. Hit 20 balls to the same spot and watch whether they’re struck at the same height. Inconsistent height usually means your body is bouncing.

Check 3 · The lean-back check. Have a partner watch you loop from the side: does the body fall back as you load? The weight should go forward on a loop, not back.

Check 4 · The reset check. After each stroke, does the weight return to the middle? If you need a pause before you can reset, your recovery is too slow.

A Quick Self-Check

Bend the knees, stay low, weight on the balls; keep your head on one level line; forward, back, and side to side are free; just don’t bob up and down.

One Reminder

Your center of gravity is the foundation of every technique.

If the foundation shakes, no stroke you build on top will hold. Next practice, before you chase quality, spend five minutes on one thing only: is my body height staying constant?

Once your weight is steady, the next step is learning to actively move it — that’s what upgrades it from passive stability to an active weapon. Further reading: Controlling Your Center of Gravity.