Touching BasesMarch 25, 2010
Most Impvoved PITCHf/x Pitches of 2009
By Jeremy Greenhouse

At Fangraphs, you can find the most valuable pitches in baseball. FanGraphs uses Baseball Info Solutions data and assigns pitches a run value based on the results of each pitch. Tim Lincecum's changeup comes out on top. A couple weeks ago, I tried my hand at finding the best pitches of 2009 by using PITCHf/x data and assigning each pitch a run value based on the pitch's physical characteristics. I didn't grant a winner, but gun to my head,* I'd have to say Matt Thornton's four-seamer or Zack Greinke's slider. As I learned in 8th-grade tee ball, no award series is complete without handing out trophies for the most improved. (Thanks again Coach Hover!)

*Actually, gun to my head, I'd have to say, "Please stop holding a gun to my head." I can't imagine anyone would be willing to use lethal force to obtain my opinion on this matter.

A quick-and-dirty, yet effective, way to tell whether or not a pitcher has improved in a given year is to simply find the difference in his fastball velocity from the previous year. Check out Dave Allen's take from this time last year. In 2009, Homer Bailey, Carl Pavano, Barry Zito, Justin Verlander, and Jon Lester all exceeded expectations. Their success could be tracked back to substantial increases in fastball velocity. I'm hoping that by looking at differences in "fxRV," which incorporates measures of velocity as well as movement and location, I will be able to find some pitchers who improved their fastballs by sacrificing velocity in favor of movement or command. Here are the top five most improved fastballs of 2009. The velocity delta is represented in terms of miles per hour and the fxRV delta in units of run value per 100 pitches.

Pitcher Pitch Type Velo Delta fxRV Delta
Mark Lowe F4 1.66 -0.87
Wandy Rodriguez F2 0.87 -0.69
Joel Pineiro F2 -0.65 -0.60
Scott Feldman FC 0.91 -0.55
David Aardsma F4 -0.57 -0.50

Mark Lowe's fastball jumped from Jon Garland to Jonathan Broxton quality. Velocity was evidently the trick for Lowe, who upped his pre-2009 four-seam velocity from 94.6 MPH to 96.2 MPH. Wandy Rodriguez also greatly benefited from a boost in velo, but at the same time, he managed to add sink to his two-seamer. That's a tough task to pull off. Scott Feldman's cutter was one of the most valuable pitches in baseball last year, and there's good reason why. He broke the 90-MPH threshold with the cutter while generating an extra inch of horizontal movement. He threw it about twice as often in 2009 as he did in 2008. It wasn't the best cutter in the game—we know who that belongs to—but it was easily the most improved.

And then there's Joel Pineiro and David Aardsma. I'm not sure what I can possibly add to the discussion concerning Joel Pineiro and his sinker. I love that the numbers back up the excessive number of stories. Pineiro traded velocity for movement and command, and it made his sinker a better pitch that yielded better results. Pineiro's fastball was thrown 71% of the time last year as compared to sub-60% in years past, and its effectiveness went from 20 runs below average to 20 runs above average. I think that PITCHf/x data can be an aid to coaches in that the data can show what pitchers might want to focus on in terms of release point, velocity, movement, or location. I think Dave Duncan might inherently possess this knowledge. There's an adage that sinkerballers with tired arms throw heavier and better sinkers. PITCHf/x data can determine if the adage holds water.

Aardsma threw the highest rate of fastballs in the league last year at 87%, and he did so because he traded in velocity for overall quality. And like Pineiro's sinker, Aardsma's impressive four-seamer was well chronicled. Geoff Baker doesn't miss a beat.

The other key was Wetteland, pitching coach Rick Adair and manager Don Wakamatsu convincing Aardsma he didn't have to blow hitters away by overthrowing. They told him his fastball could still get hitters out if he took a little off it in order to hit his targets more consistently.

"If your strength is a fastball, then your strength is a fastball," Wetteland said. "Just work on where you can control it to all spots of the zone. Get the control down to the point where you can do what you do best..."

The key to me was, if I was already beating them with my fastball, don't try to throw it any harder," Aardsma said. "Whenever I get in trouble, it isn't because I'm throwing fastballs, it's because I'm getting behind in the count with them.

In addition, Dave Allen found reason for Aardsma's four-seam improvement.

At the other end, Rich Hill's four-seamer was the antithesis to Lowe's. Pre-2009, both pitchers' fastballs were mediocre. Lowe's became one of the best in baseball whereas Hill's became possibly the worst.

As for the most improved breaking balls...

Pitcher Pitch Type Velo Delta fxRV Delta
Ubaldo Jimenez SL 0.24 -0.66
Erik Bedard CB 0.23 -0.62
Justin Verlander CB -0.28 -0.62
Barry Zito CB 2.42 -0.59
Zach Duke CB 0.25 -0.57

Ubaldo Jimenez found his slider last year, and he didn't shy away from it. In 2008, Ubaldo ran his fastball at 94.9 miles per hour. Even though no starting pitcher threw harder than his 96.1 MPH in 2009, Ubaldo actually dropped his fastball usage to 62.7% in 2009 against 69.8% in 2008. That's because his slider was his most improved pitch. I'm having trouble pinpointing exactly what Jimenez changed, but I think it was just a matter of throwing more strikes. Justin Verlander's curve was an entirely different animal last year. Same velocity, but twice as much movement. Erik Bedard's curve has always been really, really good. It was possibly the most unhittable pitch in baseball last year, though.

Meanwhile, Cole Hamels' curveball regressed so badly last year that he might want to rethink the pitch. He didn't throw it for strikes, he didn't get any swings, he didn't get any whiffs. I'm not sure what he was trying to accomplish with the curve last year, but he didn't get it done. Buster Olney reports that Hamels is indeed working on his curve.

I'm skeptical that the fxRV system adds any value to measuring the effectiveness of changeups and other off-speed pitches, since they're mainly built on deception and sequencing. Anyway, as compared to past years, Justin Verlander's change had better fading action, and Ryan Dempster's splitter had better bottom.


Jeremy, these posts are amazing!
Where was Joba Chamberlain in terms of fastball regression this year? I figure he'd be pretty high on the list.

Lucas, yes, Joba certainly regressed, as evidenced by his drop in velo. I might do a post on the difference in pitch quality between starting and relieving among pitchers.