[whip]

Knudson practiced with a cigarette or a golf pencil in his mouth for the same reason. A drill he used with students who needed to stay more stationary or alternatively for students he wanted to just plane shut up. Hard to talk with a pencil in your mouth.

U shouldn't let the head bob or sway but if u really wanna get precise also don't let it turn tilt or swivel either the weight of the head and the picture of the ball moving around during the swing is hazardous