Posted by BaconSlayer09
On July 31st, Edwin Jackson owned a 5.16 ERA and a 4.27 FIP. Ever since, his ERA is a microscopic 1.47 in 5 starts, where he has gone at least 7 innings in every single start. His 11.05 K/9 and 1.96 BB/9 has resulted in a 2.37 FIP. He has been worth 1.4 WAR in only 5 starts, which is only .5 wins off from his production in 4 months with the Diamondbacks. This torrid stretch has resulted in his ERA dipping from 5.16 to 4.37 while his season FIP and xFIP are both at 3.86. So is this a fluke and if it isn’t, how did the change come about so quickly? Let’s find out.
First thing’s first, we need to find out if what Edwin Jackson has done in this past month is real or not. The first thing to look at to see if a pitcher is getting lucky or unlucky is BABIP. Jackson’s .316 BABIP is definitely not Trevor Cahill-low and it is on par with his career mark of .310 as well as his .318 mark with the Diamondbacks earlier in the year. His 12.5% line drive rate suggests that this .318 mark is far too high, as his xBABIP is in the neighborhood of .250. So from the looks of this, Jackson has been unlucky, which is sort of hard to believe since his FIP is a whole run higher than his ERA. And before anybody starts talking about how he’s only faced the Orioles, Tigers, and Indians in his 5 starts, I get it and I’ve taken that into account. Either way, Jackson’s performance thus far has not been a fluke. That much is for sure.
So we now know that Jackson’s 2009 Zack Greinke-like 5 start stretch is nothing like the first 3 months of the season for Brennan Boesch, but why is he so effective now? This is actually very hard to figure out, because getting a new pitching coach and going to another league contains many factors that are immeasurable, in other words, there are lots of intangibles involved. So from an intangibles point of view, the guy who should get a lot of credit has to be Don Cooper. Cooper wanted Edwin Jackson, almost as much as he wanted Matt Thornton back in 2006. Look where Thornton is now. I’ll tell you this: when Don Cooper knows what he’s working with, he’s very good at his job. And it’s not even anything complicated. Cooper usually tells his pitchers to relax, avoid thinking about walks (or the W word), and have good body language on the mound. His reclamation projects, most notably Matt Thornton and Gavin Floyd, were guys with lots of stuff, but little control and mound presence.
The same can be said about Edwin Jackson, who could very well be his third notable reclamation project. Apparently, Cooper corrected a couple of things with Jackson, who was tipping his pitches. Cooper also told Jackson to stand more upright. This resulted in his push-off leg being more upright during the delivery. All of this, plus other things not mentioned, has resulted in Jackson halving his walk rate from 4.02 to 1.96. His better control has also led to a huge increase in his K rate, going from 6.97 to 11.05.
But why? Why are these rates so much higher? One thing could be his increase his velocity. Jackson threw his fastball at 94 MPH with the Diamondbacks, with a 94.1 career average. In his 5 starts with the Sox, Jackson’s velocity has jumped 1.4 MPH to 95.4, a very big difference for a starter. His velocity for every single pitch in his repertoire have also gone up. His slider is now at 88, 3 MPH faster than it was with the Diamondbacks. His change-up and curveball have also seen 2 MPH increases. All of this is most likely due to Cooper’s mechanics changes because at this time of the year last season, Jackson was falling off a cliff with the Tigers, indicating fatigue.
Gaining velocity would usually indicate a loss of control, but this has not been the case with Jackson. In his 5 starts with the Sox, Jackson has increased his strike% on every single pitch type, most notably his slider, curveball, and change-up. The better velocity and higher strike% has resulted in much higher whiff rates for his slider, change-up, and curveball. Due to these factors, Jackson’s accumulated a 2.4 linear weight pitch value on his fastball and a 6.3 linear weight pitch value on his slider in just 5 starts, both of which are huge improvements over his values with the Diamondbacks (this is a counting stat, so he’s eclipsed his production with the Diamondbacks (21 starts) in just 5 starts with Chicago).
By now, you probably get it. Edwin Jackson’s production has not been a fluke, Don Cooper is a magician, and it shows in Jackson’s pitch f/x data. But is this sustainable? Will Edwin Jackson be the next Dwight Gooden? The answer is probably no, but I think there is a compromise as to where he will end up in the long term. Jackson’s 58% ground ball rate is most likely unsustainable. His 30% fly ball rate probably isn’t here to stay either. Both of these are dependent on pitch location and velocity, which Jackson has mastered. However, those rates seem far too out of the ordinary to hold up over a large sample size. In addition, his 12.5% line drive rate also doesn’t seem to be sustainable. So in part, Jackson is not this good and I don’t think everybody expects him to be this good. However, I could easily see Jackson being a guy who is capable of putting up a 3.5 ERA with a 3.5 FIP, even in U.S. Cellular Field. He has turned into a ground ball pitcher, which fits the park perfectly. Plus, he misses bats and doesn’t walk people, what’s not to like?
Edwin Jackson might not be the next Zack Greinke, but Don Cooper has turned him from an underachieving phenom to a possible top tier starter. When this trade was initially made, I was mad, mad that the White Sox gave up their best prospect for an underachieving pitcher with maybe a bit of upside, especially since the top prospect, Daniel Hudson, was probably as good as Jackson at the time. But I was wrong, as were many others who scratched their heads at the move. A month later, Kenny Williams is looking like a genius, once again. You really wonder how he pulls this kind of stuff off, even if it cost him $8 million and a pretty good pitching prospect.