Touching BasesMarch 04, 2010
Best PITCHf/x Pitches of 2009
By Jeremy Greenhouse
The PITCHf/x system uses two cameras to track pitches between pitcher and batter, determining the coordinates of the ball x(t), y(t), z(t) at times t in 1/60-sec intervals. The resulting trajectory is a nine-parameter (or 9P) fit corresponding to constant acceleration in each of the three coordinates. The 9P fit is an approximate solution to the exact equations of motion. All quantities reported in the PITCHf/x data base, such as the pitch speed, the location of the pitch as it crosses the plate, the break (or pfx) of the pitch, etc., are derived from the fitted trajectory rather than from the original data. -- Alan Nathan

Velocity, movement, location, release point are age old-terms in the baseball lexicon that have been quantified thanks to pitchf/x. Chris Moore in August published a groundbreaking study ranking the best fastballs in baseball using factors given by pitchf/x including velocity, horizontal location, vertical location, horizontal movement, and vertical movement. I will try my hand at a similar analysis. The goal is to measure a pitch's quality using only the inputs provided by pitchf/x. I've decided to use the same five parameters as Moore, also opting against adjusting for release point, and instead simply excluding all pitchers I classified as sidearm. I've tried to control for count and handedness as well. I'm calling the metric fxRV, as its units are in terms of run value.

Top Five Fastballs

Player Type Pitches Usage rv100 fxRV100 Velocity
Matt Thornton F4 857 75.04% -1.42 -1.27 95.74
Lance Cormier FC 617 51.25% -1.68 -1.11 87.46
Cliff Lee FC 587 15.31% -0.38 -0.96 85.85
Justin Verlander F4 2220 57.05% -1.29 -0.81 95.99
Jason Motte F4 634 68.32% 0.04 -0.77 96.17

Matt Thornton has top five stuff of any reliever in baseball and Justin Verlander has top five stuff of any starter. That type of velocity from a respective lefty and starter is unparalleled. Clayton Kershawas a left-handed starter will be entering that territory soon with his 94-MPH fastball. Verlander elevates his fastball more than just about anyone in the game with the exception of Kevin Millwood. According to FanGraphs, Lance Cormier has increased his cutter percentage each of the last four years to the point that he is now throwing it over half of the time. And looking at his pitch type values, he might want to entirely scrap his four-seam fastball, since it has never been an above average pitch while his cutter was fantastic last year. I'm puzzled by Motte's poor run value on his fastball. He's too good to fail as a reliever. Patience, TLR.

My numbers say that Danys Baez' fastball is in line for some regression this year, despite successful results. At the other end of the spectrum, Baez' teammate Chris Tillman has a quality fastball, even though it was ten runs below average last year. And Barry Zito's fastball is aggressively bad.

Top Five Breaking Balls

Player Type Pitches Usage rv100 fxRV100 Velocity
Erik Bedard CB 438 32.57% -1.50 -1.85 77.67
Zack Greinke SL 765 22.12% -2.90 -1.57 85.63
Gio Gonzalez CB 515 28.61% -1.41 -1.48 78.68
Bronson Arroyo CB1 596 17.85% -2.00 -1.47 75.00
Daniel Bard CB 221 25.46% -2.12 -1.46 83.93

Erik Bedard* and Gio Gonzalez both have big yakkers. Watching these guys on TV is fun, since a sweeping curveball from a left-handed pitcher as viewed from the off-center center field camera appears to be heading right for a left-handed batter's skull only to break over the inside part of the plate, hopefully as the batter's knee buckles: the old Barry Zito phenomenon. Joe Posnanski has called Zack Greinke's slider "devastating," "the best in the American League", and "his "God-given gift." It's a good pitch. Bronson Arroyo is to pitch classification systems as Bronson Arroyo's name is to Tim McCarver's brain. Nevertheless, his curveball(s?) are good pitches.

Kevin Jepsen didn't qualify for the leaderboard, but his curveball is superb. It gets similar movement to Bedard's curve, but comes in six miles per hour faster, albeit from the right side. Jepsen gets his curve down in the zone very well, too. He also throws a 96 MPH fastball and 90 MPH slider. I'm very, very high on Kevin Jepsen. Jonathan Broxton's four-seam fastball and slider were both within a spot of the top five. Daniel Cabrera? Yeah, he's bad.

*Ironically**, there's also a Canadian speed skater named Eric Bedard. If short track were regularly televised, I swear I would watch.

**I find it ironic that I don't know what irony means.

Top Five Off-Speed Pitches

Player Type Pitches Usage rv100 fxRV100 Velocity
Burke Badenhop CH 142 12.40% -1.88 -1.09 82.19
Bronson Arroyo CH 518 15.51% -1.98 -0.92 79.29
Jered Weaver CH 594 16.56% -1.36 -0.84 80.21
Brandon League SF 181 16.54% -2.32 -0.80 85.22
Sean O'Sullivan CH 145 16.08% -3.56 -0.78 76.13

The four pitchers besides Brandon League are all on this list because they can command their off-speed pitches. Nothing in my system accounts for the deception of a change. League's splitter, however, was labeled by Matthew Carruth as the toughest pitch in the league to hit because of its 35% whiff rate. Burke Badenhop does a terrific job of getting his changeup down and away from opposite-handed hitters, and his pitch has a lot of "sink." Jered Weaver and Sean O'Sullivan generate a lot of "rise" on their changeups, though that's not necessarily a good thing, since Clayton Kershaw gets the second most rise on his change in the league, but it's a highly crude pitch. He can't locate it either.

Interestingly, Jonathan Papelbon had one of the worst splitters in baseball last year. He rarely threw it in the strike zone. I was happy to see that Daniel Ray Herrera's screwball was listed as a quality off-speed pitch. The world needs more screwballs.


It makes sense that Papelbon's splitter was rarely in the strike zone. He usually throws it when he's way ahead in the count, into the dirt or a bit above, to try to get someone fishing. Also, he can use it to change the eye level of a hitter, say throwing a splitter in the dirt on 0-2 and then going with a shoulder-high fastball on 1-2.

If it's their best pitch, why do they only use it 15% Does it lose effectiveness with more exposure?

Pat, you're right that Paps might be setting up future pitches.

WC, exactly. No matter how awesome Greinke's slider is, if the batter knows it's coming, it's getting hit. Gotta randomize.

*Ironically**, there's also a Canadian speed skater named Eric Bedard. If short track were regularly televised, I swear I would watch.

**I find it ironic that I don't know what irony means.

The first statement is not ironic, just a curiosity. The second statement is much closer to irony.

Irony would be someone being given reams of sabermetric data on Albert Pujols, discounting it because he only likes average, homers, and rbi, and concluding that Pujols is therefore even better than the statheads think he is. And then turning around and saying that despite average, homers, and rbi, Alex Rodriguez is overrated because he isn't clutch.

Curious about Ian Snell - in the article you did on 'Stuff' he stood out as a guy with decent statistical stuff, but terrible run values. I'm guessing that the inclusion of location data would explain a lot of this. What's his fxRV100 for the FB and Sl?

(This is great, great stuff)

Ian Snell is also a guy who has a lower perceived velocity than actual, due to his release point. Eric Seidman had a great series on this at BPro.

That's true Nick, but I wonder if this wouldn't help explain more of his struggles. I mean, his apparent velocity is slower, but it doesn't seem that that explanation is enough on its own. We'll see I guess.


I would be *very* interested to see this same analysis applied to 2008 data. I've always intended (but never had time) to split my analysis up by year to see how reliable the measures are. Matt Thornton had very similar years in 08, 09. Does he stay on top? Great stuff!

Marc, can't say I remember pointing out Ian Snell, but I'll look at the data anyway.

I don't see any significant split in his fxrv and stuffrv numbers. He has a bad fastball in both, and fine breaking balls.

Chris, I used all f/x data I deemed valid since 2007 to build my model. Predicting the same set of pitches by year and pitcher, I have Thornton's 2008 four-seamer as the best fastball in my entire data set at -1.66 runs and his 2009 four-seamer as the second best fastball at -1.62 runs (per 100). How's that for consistency?

Jeremy, can you do a y-t-y correlation testing of Pitch f/x ERA, as well as a Pitch f/x ERA to regular ERA in Year N + 1? Basically, how does Pitch f/x ERA compare to FIP or tRA in terms of predictiveness?

Sorry Jeremy - I should have said the 'spreadsheet' that you did that accompanied the article.

Snell and Miguel Batista stood out as guys with good (that is, negative) scores for stuff RV100, but terrible, terrible results. They were the opposite of the Justin Duchscherer/Greg Maddux pitchers who had very good results despite awful pure stuff.
Anyway, it seems interesting if when you run the numbers now, using an expanded definition of stuff, that Snell is terrible on both metrics. I was thinking that the definition of stuff may have changed to include location, but I'm not sure.