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.