While I was busy looking at increases and drops in fastball speeds, I also made note of the frequency with which fastballs were thrown by each pitcher. As noted previously, changes in fastball speed appeared to have no overwhelming correlation with changes in how often pitchers used their fastball.

Which pitchers did deviate the most from their 2008 ratio then? Glad you asked. Here are the top twenty greatest reductions in fastball usage, according to BIS pitch typing, with a minimum of 50 innings pitched in both 2008 and 2009.

Brian Bannister, -42.8%

Scott Feldman, -19.1%

Sean Marshall, -17.2%

Pat Misch, -15.5%

Nick Masset, -15.2%

Dan Wheeler, -14.8%

Braden Looper, -14.3%

Daniel Cabrera, -13.1%

Brandon Lyon, -12.9%

Tony Pena, -12.8%

Juan Cruz, -12.8%

Scott Kazmir, -11.2%

Mariano Rivera, -11.0%

Ryan Franklin, -10.5%

Brad Ziegler, -10.4%

Tim Lincecum, -10.3%

Cla Meredith, -10.2%

Matt Capps, -9.9%

Lance Cormier, -9.8%

Chad Billingsley, -9.5%

Brian Bannister is obviously a special case as he all but abandoned his traditional fastball in favor for a cutter in 2009. Scott Feldman too went to more of a cut fastball in 2009, explaining his drop. There are legitimate departures on this list however. Sean Marshall tossed a breaking ball about 14% more often in 2009. Pat Misch fell in love with his slider and changeup. Scott Kazmir returned to his pre-2008 fastball and slider levels.

The reverse list also has some interesting names on it. The top twenty greatest increases in fastball usage.

Jamie Moyer, 18.4%

Miguel Batista, 15.7%

Joel Pineiro, 12.6%

Guillermo Mota, 12.3%

Francisco Cordero, 12.0%

Nick Blackburn, 11.1%

Aaron Laffey, 9.4%

Jesse Carlson, 9.2%

CC Sabathia, 7.8%

Clay Buchholz, 7.4%

John Lannan, 7.1%

Brad Lidge, 6.9%

Francisco Rodriguez, 6.8%

Brian Bass, 6.5%

Derek Lowe, 6.4%

Hiroki Kuroda, 6.2%

Justin Masterson, 6.1%

Matt Thornton, 5.9%

Russ Springer, 5.8%

Jarrod Washburn, 5.8%

Joel Pineiro developed his sinking fastball to great lengths this season. Given that his fastball has never been a good pitch, one wonders why Jamie Moyer relied so much more on it in 2009, to his detriment.

A lot of late inning relief aces appear on this list too, to mixed results. Francisco Cordero‘s fastball improved in efficacy a lot in 2009. Brad Lidge‘s went into the toilet and Francisco Rodriguez’s stayed just about the same, as did Mota’s.

Obviously there is not much of an overarching theme at play here. Each pitcher has his own particular reasons for appearing in one of these two lists and many of those reasons are unique. I present the information mostly for the sake of information’s sake. Make of it what you will; I am going to go see if I can tease out any patterns based on disabled list appearances.