The knuckleball is an intriguing prospect from the outset. How can something which is sometimes not even thrown at 70mph compare to something thrown at 95+ mph by some fireballers (Jonathan Papelbon, Joba Chmberlain et al)??
Having experienced Tim Wakefield pitch live twice, it really is hilarious. The ball looks like it floats out of his hand towards large burly major leaguers. To see them swing violently and miss at something so slow is amazing. Which begs the question, what is the Science behind the knuckleball? As alluded to in the Ronaldo post, the principles isolated in this pitch are quite similar. The distinct lack of spin imparted to Wakefield’s pitch and Ronaldo’s strike results in the respective balls making erratic movements on the way to their targets due to increased drag, results in the goalkeeper and hitter, respectively, having trouble anticipating where the object ball will be on arrival.
Further information from the Am.J. Physics here.

Wakefield elucidates this lack of spin by using a special technique. The grip is extremely distinctive, he essentially digs his fingernails into the ball with his little finger at the side of the ball to ensure stability, so that at release point his fingers essentially push the ball towards the target, as opposed to the natural spin put on the ball as is the case with a “normal “ fastball. This results in the ball being thrown at a much lower velocity than regular MLB pitchers. The upside to all this is Wakefield has very little wear and tear on his arm, he can pitch longer into games and pitch more innings every year. He has also aged very well, he is now in his 42nd year, and still in good shape with the Boston Red Sox.
A video showing the pitch can be seen here

-Brian (brian.c at lifescience.ie)