What is the purpose of a knuckleball? And can you really count the threads on a knuckleball (or knuckle ball) as it doesn't spin? And are knuckleballs still thrown in professional baseball?

I have read that the "knuckleball" does not impart the rapid spin that causes a curve. Instead,
the ball may behave erratically, curving unpredictably when close to the plate, making it hard
to hit.

As I recall, the spin of a thrown baseball imparts stability, much like function of the spin on a bullet fired from the muzzle of a rifle.

A knuckleball substantially lacks spin, and therefore is more subject to the random, unpredictable effects of stray breezed and puffs of wind. It is as unpredictable to (and as unbeloved by) the catcher as it is to the batter.

Keiva: you are not welcome on AWADtalk.

The person known as Keiva, who recently posted on this thread, was banned for flaming. He forced his way back into this forum by implied threats of legal action against Anu Garg, the founder of AWAD. This same person has also been known to post under the names AphonicRants, KeivaCarpal.