Roberto Hernandez is Not Fausto Carmona
by Bradley Woodrum - April 24, 2013
http://ppt.cc/HhDV
Yes, well obviously Roberto Hernandez is not Fausto Carmona. The name Fausto
Carmona belongs to someone else, and though the history of Cleveland Indians
starting pitcher “Fausto Carmona” belongs to Roberto Hernandez, the two
pitchers (the one pitcher) are not the same.
What I’m saying is: Roberto Hernandez is striking out batters.
He has a 22.5% K-rate right now. His previous career high was 17.1%, but that
was mostly as a rookie reliever. As a starter, his highest K-rate was 15.6%.
In fact, if we dig even deeper, we find his 22.5% K-rate is the highest
strikeout rate he’s ever posted over a four game period:
http://cdn.fangraphs.com/blogs/wp-content/uploads/2013/04/4-game-K-rate.png
His recent success — underscored and even underappreciated in his 3.75 FIP
and 3.60 SIERA — appears to be the product of deliberate changes. That
suggests he could maintain a new level of success.
Earlier this month, Michael Barr observed Hernandez had changed his pitch
selection distribution, leading to new success against lefties. Barr astutely
points out how Hernandez has struggled to strikeout lefties. He has a career
17% K-rate against righties, but only 11.% K-rate against lefties.
So far in 2013, Hernandez has a 21% K-rate against lefties and a 26% K-rate
against righties. And it does not appear to be (solely) a trick of Jose
Molina called-strike magic or the sort. His swinging strikes per pitch have
also skyrocketed:
http://ppt.cc/J2GB
Could this be a four-game fluke? No. Because it has already lasted eight
games. In 4 Spring Training starts, Hernandez faced 111 batters and struck
out 25. That 22.5% K-rate perfectly mirrors his present 22.5% K-rate.
Hernandez has changed something, and the result has been more Ks. Whether or
not the hitters adapt and bring his K-rate back down is a different
discussion, but it appears that the uptick in Ks — and thereby production —
is no accident.
So what has Hernandez changed?
I am not a big fan of PITCHf/x pitch classifications, specifically the ones
the MLB spurts out with the raw data. I think it can be more instructive to
look at a visualization of the data and look for the pitches and changes to
the pitches there. Look, for instance, at the pitches outlayed below. Click
the box next to 2011 and see if you can spot differences in the pitch
movement and/or velocity (with velocity denoted by the icon color):
(因无法缩图 so下图请到Fangraph网站上看)
What did you notice? I noticed a slower, more sweeping slider. Sure enough,
it appears the increased movement and increased effectiveness may be coming
from a slower slider. And though the slider has less velocity, the speed is
actually more in line with his previous slider velocity:
http://cdn.fangraphs.com/blogs/wp-content/uploads/2013/04/Pitch-speeds.png
His slider is now leaving his hand around 83 mph as opposed to the 86 mph
slider he was throwing — with mixed success — in preceding years.
Meanwhile, his changeup has maintained a 5 mph difference from his main
pitch, his 91 mph sinker. But he’s throwing that changeup like mad.
He has thrown 287 pitches to left-handed hitters in 2013, and 104 of those
twirls were changeups. That’s a 36% changeup rate, up from his career 23%
changeup rate to lefties. In 133 pitches to right handers in 2013, he has
slung 33 changeups. That’s a 25% rate against his career 7% rate.
Here, look at it:
vsLHB Total Pitches CH Rate
2008 1077 143 13%
2009 1299 246 19%
2010 1796 375 21%
2011 1516 464 31%
2012 140 46 33%
2013 287 104 36%
Grand Total 6115 1378 23%
Starting in 2011, he started using the changeup more, but now both hands are
getting the Change Treatment:
vsRHB Total Pitches CH Rate
2008 918 25 3%
2009 936 129 14%
2010 1495 33 2%
2011 1482 107 7%
2012 89 3 3%
2013 133 33 25%
Grand Total 5053 330 7%
FanGraphs alumnus Tommy Rancel and BP’s Jason Collette dissected Hernandez’
s changeup uptick on The Process Report and suggested sequencing benefits I
too suspect:
To date Hernandez has held opponents to a .264 wOBA with his changeup and
a .178 wOBA with his breaking ball. It’s not too surprising given the
quality of the pitches and the improved usage and sequencing at hand.
While the early returns have not been golden, the silver linings are now
more visible than before.
One of the element Collette keys on in that article is the pitch placement,
specifically how Hernandez has been dropping the changeup low in the zone
with success. We can expand that thought using this visualization:
(因无法缩图 so下图请到Fangraph网站上看)
One of the curious location choices I noticed was how he is placing his
sinker up in the zone, away in the zone, inside the zone, out of the zone,
everywhere. (Click on the SI to highlight his 2013 sinker usage, then check
the box next to “R” or “All” to reveal all the sinkers he’s thrown in
2013.)
In the past, Hernandez kept the sinker in a very specific band in the
lower-left portion of the zone, regardless of batter handedness. We can see
this more clearly with the PITCHf/x heatmaps on his player page, here enGIF'd:
http://cdn.fangraphs.com/blogs/wp-content/uploads/2013/04/Sinker-GIF.gif
Why is he putting the sinker any and everywhere in 2013? I don’t know. It
could be spotty command (though his 9% walk rate is in line with career
norms); it could be a function of small samples; or it could be an effect of
his revamped pitch sequencing.
Let us study, as an example, Hernandez’s strikeout of left-handed batter
A.J. Pierzynski in the bottom of the 4th inning on April 9, 2013. This is the
pitch sequence and result:
Pitch 1:
Sinker high and away. [Ball 1.]
Pitch 2:
Changeup middle-away. [Foul ball, 1-1.]
Pitch 3:
Sinker middle in. [Ball, 2-1.]
Pitch 4:
Changeup low, low, middle. [Whiff, 2-2.]
Pitch 5:
Sinker up and in. [Called strike, K-looking.]
The last two pitches in context:
http://cdn.fangraphs.com/blogs/wp-content/uploads/2013/04/Sequence-GIF.gif
Pierzynski is about 15 minutes late on that sinker — even though the pitch
is not in that lower-left (or down-and-away) sweet spot that Hernandez
formerly abused. Could it be a function of the pitch sequencing or placement?
Does the changeup followed by the sinker look like changeup again?
Judging by Pierzynski’s reaction, he was looking for another changeup. One
of the observations we can make from the pitch movement Tableau is that
Hernandez’s sinker and changeup have almost equal horizontal movement, but
are a good five inches apart vertically — and nearly 6 mph different in
speed. The slider has similar speed to the changeup, but completely opposite
movement.
By working off his changeup instead of his sinker, Hernandez may be more
fully able to take advantage of his other to main pitches, his sinker and
slider. The changeup has visual similarities to both of his other key
pitches, but the transitive property does not apply, as the slider and sinker
have few visual links — they are very different pitches.
Linear weights can play tricks on PITCHf/x data. Certain pitches may solely
serve the purpose of setting up other pitches, so a strong linear weights
readout on one pitch may be the product of it simply looking like a better
pitch. Nonetheless, it is unsurprising to see both Hernandez’s changeup and
slider earning strong linear weights results so far in 2013.
What makes Hernandez so interesting? Why study a fifth starter so much? Well,
it starts with the Rays front office. They are smart. They make a lot of
low-cost, high-reward gambles — all small market teams do — but they seem
to have succeeded on those gambles more than most. They have presided over:
Fernando Rodney morphing from a wild fireballer to the owner the reliever ERA
record; Jeff Keppinger going from an undesirable shortstop to a $12M
utilityman; and career years from Kyle Farnsworth, Rafael Soriano, Joaquin
Benoit, Grant Balfour and Joel Peralta — as well as hitters Casey Kotchman,
Carlos Pena, Eric Hinske and possibly now James Loney.
At some point, the Rays’ success with these low-cost players goes from good
fortunes to tedious pattern. And given these recent changes in his approach,
it appears Roberto Hernandez may be another link in that chain.
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若不想看完整篇文章
大概有几点了解一下
1.Roberto Hernandez生涯最高K% 17.1%(但是是当RP) 本季目前是22.5%
2.本季FIP:3.75
SIERA:3.60
3.本季对左打K% 21%
右打K% 26%
然后他的表现从春训大致上就是如此了 所以应该不是fluke
文中的两个表格
Roberto Hernandez在2011年开始丢了很多变速 今年更是明显对左(36%) 对右(25%)
然后再看此文中最后一个图(Roberto Hernandez对AJP) 很明显AJP被骗了
作者看到Hernandez的变速跟sinker有相同的水平位移 但是两者却有5吋的垂直位移
且有高达6mph的速差
结论:光芒总是在沙砾(有限预算)内挑珍珠
话说投手可以教的好 但是打击都没起色阿.......