Ma long's backhand flick

Why does Ma Long cover the ball with his left hand while performing backhand flick?

He also uses his left hand for all his back hand shots.

Is that for a guidance which shows the movement of the ball? 

Regards

Bala

Hi Bala,

It is just something he does to balance himself and where his left arm ends up.

Balance is a key part of any stroke and this helps Ma Long to balance himself.