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Tuesday, November 27, 2007
Knuckleballs
John Walsh is back with another PITCHf/x article, this time focusing on Tim Wakefield. Note that all of his graphics refer to the spin-induced movements of the pitch (i.e., gravity and time are not part of the equation). What is interesting about the knuckleball is that it actually changes its spin rotation or axis on its flight toward the batter. So, what John is reporting as “fixed” spin-induced (gravity-less, time-less) movement is really its equivalent. That is, those points he is showing is the equivalent of what happens if you look only at the starting, ending, and “high” points, and try to infer the spin imparted by the pitcher. It’s highly likely that the spin that Wakefield is actually imparting is fairly consistent, but it’s just that the mid-flight effect is as if he wasn’t putting the same spin at all. I think you can write a whole book just on Wakefield.
And as I noted to John on ballhype (and many times elsewhere on this blog), when it comes to talking about “break” or what the batter really cares about, you need to show the movement of the ball which includes gravity and time. That is, we want the human definition of break.