Calling back to a post from last March...

(minimum: 60 IP both seasons, pitchers switching between the rotation and bullpen excluded)

Biggest Fastball MPH Increase, %, 2007-2008:

1. Jeremy Sowers, +5.0%
2. Jon Lester, +2.4%
3. Ervin Santana, +2.4%
4. Jose Valverde, +2.2%
5. John Danks, +2.0%
6. Jesse Litsch, +1.8%
7. Roy Halladay, +1.8%
8. Cliff Lee, +1.7%
9. Randy Wolf, +1.6%
10. Jon Rauch, +1.5%

Biggest Fastball MPH Decrease, %, 2007-2008:

1. Scott Olsen, -2.6%
2. Dan Wheeler, -2.0%
3. Tom Glavine, -1.9%
4. Francisco Rodriguez, -1.8%
5. Daniel Cabrera, -1.8%
6. Tim Wakefield, -1.8%
7. Chris Young, -1.7%
8. Manny Corpas, -1.5%
9. Jason Grilli, -1.4%
10. Heath Bell, -1.4%

Nothing extraordinary, but there you go. Note that the top list includes six pitchers who saw their tRAs improve by at least 15%, whereas the bottom list includes seven pitchers who saw their tRAs get worse by at least 15%. Velocity isn't everything, but it's clearly important.

Most interesting, I think, is Jon Lester - this past season, he exceeded his previous career-high for innings by more than 50, but he nevertheless threw his best fastball and, instead of fatiguing towards the end, saw his velocity peak down the stretch:

Some credit has to go to John Farrell and the rest of the Boston coaching staff for showing Lester how to pace himself over a full season. Given his stamina and performance, everybody involved over there did one hell of a job.

Felix, by the way, lost about a tick. Morrow gained a tick despite throwing 45% of his pitches as a starter.