In all racket sports, a well-executed serve can establish a real advantage. Badminton is played by around 220 million people across the globe and a“spin serve” took badminton by storm when a Danish player at the Polish Open 2023 badminton tournament used it to dominant effect.

Like in table tennis, a spin-serve in badminton adds pre-spin before the racket touches the shuttlecock and the natural spin determined by its feathers’ inclination angles plus the pre-spin makes the flight trajectory even more unpredictable.

Naturally, instead of expecting players to adjust and improve, the community demanded the Badminton World Federation ban it. Coaches and players said extended rallies were more exciting for fans than good serves.

Science just wants to make unpredictable less so, which led researchers in communist China to converge on answers usinf  computational fluid dynamics. They simulated the trajectories of a shuttlecock during serves under three conditions: without pre-spin, with pre-spin in the direction of the shuttlecock’s natural spin, and with pre-spin against the natural spin.


Airflow around a shuttlecock during a spin serve. Credit: Zhicheng Zhang

It undergoes three phases during the serve: the turnover phase, the oscillation phase, and the stabilization phase. Pre-spin affects the oscillating behavior of the shuttlecock, and the spin serve with pre-spin opposing the shuttlecock’s natural rotation tends to prolong the oscillation phase. The efficacy of the spin serve also depends on the rotational direction of the pre-spin velocity.

The CFD simulations of shuttlecock trajectory during spin serves can be improved by capturing shuttlecock trajectories in the real world using motion capture systems.