Started coaching adult beginners a while back and noticed almost everyone makes the same mistake in their first month — and it's not their swing.

It's footwork. Or more specifically, the lack of a split step.

Most beginners plant their feet and swing from a dead stop. Watch any rec-level player vs. someone who's been playing a year — the difference isn't a prettier forehand, it's that the experienced player is already moving before the ball arrives.

The split step is a tiny hop timed to the moment your opponent (or a ball machine) makes contact. It loads your legs so you can explode in any direction. Without it, you're always a half-second late, which makes every shot feel rushed — and rushed shots are what make tennis feel impossible for beginners.

If you're picking up a racket for the first time as an adult: before you worry about grip or strokes, spend 10 minutes just shadow-practicing split steps with no ball. It sounds too simple to matter. It's the single highest-leverage thing you can drill early.

Curious what other beginners here have found made the biggest difference in their first few months — drop it below.