A small two-footed hop timed to your opponent's strike — it makes you instantly ready to move in any direction.
The split step is the least conspicuous and most effective movement in racket sports. The physiological reason is pre-tension: landing from that small hop briefly stretches the muscles, storing energy you release in your first step — measurably faster than moving from a standstill. Timing decides it: you land exactly as your opponent strikes the ball, not before, not after. Jump too early and you're planted again by contact; too late and the effect disappears entirely. Two common faults: jumping too high — it's a matter of centimetres — and landing with straight legs instead of springing into a soft knee bend.