Paul Nyman, at THT, breaks down what makes fastballs fast.
The piece is a bit lengthy, but very interesting for anyone who is interested in pitching.
Mechanical analysis (especially of pitchers) has become somewhat popular over the past year or two, really starting with Carlos Gomez’ work at The Hardball Times. Gomez has moved on to be a minor league pitching coach somewhere, and so The Hardball Times has filled the void with Nyman, who appears to be some kind of mad scientist of pitching mechanics. Lots of charts, a few technical terms, and an overwhelming sense wonder–Nyman is a good writer with an impeccable understanding of his subject matter. I could ask for nothing more.