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September 13, 2010 Fantasy BeatVazquez's Decline of Velocity and Command
With Andy Pettitte looking at a late week return from the disabled list, news began filtering out the Yankees plan on skipping Javier Vazquez in the rotation for the third time this season. While Vazquez has returned to the rotation after those two previous sojourns, indications are this move will be a little more… permanent.
Also, Vazquez has moved away from the slider this year. That’s not necessarily a bad thing as his slider has traditionally been his fourth most effective of his four pitches. However, it has served to set-up his other pitches - namely his curve and change. What follows is a table breaking down each pitch by frequency thrown by Vazquez over the last three seasons. This season represents a significant departure from his recent (and successful) approach.
By throwing fewer sliders and more curves and change-ups than in the past, it’s rendered all three pitches less effective. The loss of velocity of his fastball, combined with that declining effectiveness means Vazquez is really having difficulty keeping hitters off balance. When you look at his .264 BABIP, you may think he’s been a bit unlucky. That’s the lowest rate of his career and is well below his .300 BABIP he’s averaged through 13 big league seasons. However, hitters are making contact on 80% of his pitches this year, also the highest rate of his career. Even though his batting average on balls in play is low, there has been more contact this year and more balls in play. He’s basically running on the pitching treadmill from hell.
I highlighted the key areas in red… Large decline in the percentage of his fastball and slider thrown for strikes and the corresponding decline in whiff percentage on his curve and change. Like most pitchers, Vazquez likes to start his opponent off with a fastball, although his second choice on first pitch is his slider. He’s throwing both the fastball and slider for fewer strikes this year, so he’s not jumping ahead in the count as frequently as he did in 2009. That correlates to a decline in whiff rates on his curve and change... Because he’s falling behind in the count, hitters are wisely laying off the curve and change (historically Vazquez’s best pitches) that fall out of the zone. Fewer swings, plus more pitches out of the zone, equal more walks. His walk rate has jumped so much, his 1.36 WHIP is his worst rate since 2000.
Craig Brown is an author of Baseball Prospectus. 5 comments have been left for this article.
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Just curious -- what the source of your data?
Those numbers line up with the MLBAM classifications of the PITCHf/x data, which you can find at pitchfx.texasleaguers.com.
From my quick look at the data, I think MLBAM is over-eager on classifying the curveball this year, lumping in some sliders with the curves, whereas last year they were lumping in some curves into their slider classification. Whatever the classifications, though, as Craig pointed out, the whiff rate on everything is down from decent rates last year on the offspeed stuff and good rates on the fastball to well below league average this year on offspeed whiffs and merely average on fastball whiffs.
Thanks, Mike. Good to know about the classifications. Is that something that can be inconsistent from park to park? Same for the radar gun? It seems like the gun at Kauffman Stadium has been "hot" this year.
Ross Paul tweaks his neural net classification algorithm for MLBAM from year to year and sometimes tunes it for specific pitcher repertoires. Neural nets can be very sensitive to noise on the inputs, so a small change in speed or movement of a pitch can result in different classification by the neural net.
That in itself shouldn't be sensitive to parks, but the classifications are run on un-corrected PITCHf/x data, so if there is a calibration problem with the PITCHf/x cameras in a given park, it can affect the accuracy of the classifications from that park. I don't see that that's what happened with Vazquez, necessarily, but I haven't checked closely.
I talked some about pitch speed calibration errors in the comments to Kevin's article a week or so ago:
http://www.baseballprospectus.com/article.php?articleid=11907
I wrote about that topic more thoroughly at THT Live later that day (Sept. 3rd), but I don't know if it's kosher to post a link to that here.
Yep... I got the info from Texas Leaguers. Sorry about that, I usually mention them, but this time I forgot.
Here are the links:
2010 season:
http://pitchfx.texasleaguers.com/pitcher/134320/?batters=A&count=AA&pitches=AA&from=4%2F1%2F2010&to=9%2F13%2F2010
2009 season:
http://pitchfx.texasleaguers.com/pitcher/134320/?batters=A&count=AA&pitches=AA&from=4%2F1%2F2009&to=10%2F13%2F2009
2008 season:
http://pitchfx.texasleaguers.com/pitcher/134320/?batters=A&count=AA&pitches=AA&from=4%2F1%2F2008&to=10%2F13%2F2008