Flexibility of racquet?

[Ztail]

What does the flexibility of the racquet do? I realize that some racquets are stiffer while others are more flexible. Thanks in advance.

[Iwan]

What does the flexibility of the racquet do? I realize that some racquets are stiffer while others are more flexible. Thanks in advance.
A more flexy racket allows for more power during normal swings: lobs and clears. A stiff racket offers more smash power, if you have the arm power to go with it as it resists the shuttle's momentum better.

[Jinryu]

The flexibility of a racket refers to its shaft. A more flexible shaft will bend more during a swing, storing potential energy, and releasing that energy on impact if timed correctly. Simply put, a flexible racket helps a player with their power shots such as clears and smashes, by adding a 'spring' effect to their hits. A stiffer racket in comparison requires more of the force of a swing to come directly from the player. In general, advanced players prefer stiffer rackets, because from playing they have developed the physical strength to generate their own power and because stiffer rackets provide more accuracy.

I think it's important to emphsize that when Iwan says stiff rackets have more smash power, it it conditional-- it requires good technique and a strong arm.