Featured image courtesy of Zimbio.com: (July 6, 2018 – Source: Brian Davidson/Getty Images North America)
At this point, it is pretty clear what has been wrong with Red Sox reliever Joe Kelly. For the first two months of the season, he was possibly the team’s best relief pitcher and became a local legend for the whole Tyler Austin ordeal. The past month and a half, however, has not been fruitful for the 30 year old, to say the least.
Let’s go to the splits for Kelly’s 2018 season:
That table should be pretty easy to interpret. Kelly has been really bad since the month of June began after being really good for a considerable period of time. He has gotten hit harder and has lost complete control of the baseball during this most-recent stretch. In fact, since the month of June began, he has walked 7.6 batters per nine innings. Moreover, he has walked the same amount of hitters as he has struck out.
In terms of contact against him, his Hard Contact% against is virtually unchanged during these periods. Oddly, his Hard% was actually higher from March to May than it was from June through July. His problem, rather, has been his inability to churn weak contact. During his “good” period, his Soft Contact% was around 30 percent. That has fallen precipitously and has been almost cut in half to around 15 percent.
It has not been a lack groundballs that have spearheaded this drop off; it has been a lack of infield fly balls. He featured a 29.4 IFFB% in March-May, which is demonstrably higher than the 6.7 IFFB% he has collected June-July. When he was doing well, Kelly was garnering nearly a third of his fly balls into almost automatic outs. Between this and the walks, yeah, pieces are starting to fit together.
Check out this line graph courtesy of Brooks Baseball:
Ignoring the data point from 3/18 because he only made one appearance in March, an outlier in his four-seam usage emerges. After using his heater close to 60 percent of the time in June (and most every month since 2017), his 4-seam percentage has fallen to around 30 percent in July. Perhaps he decided to try something different after his tough June. Obviously, it has not worked very well, as his secondary pitches have not been good enough to compensate.
The velocity on his four-seam fastball is down this month, too. After averaging 99.19 mph in the previous month, in July he has averaged 97.82 mph. This could be a case of pitch misclassification where some of his sinkers (his slower fastball) lost some movement and were classified as four-seamers, bringing down the overall average. While this is plausible, there is also a chance he could (maybe) be pitching hurt or the grind of the season has overexerted him. That is a pretty drastic drop off month-to-month, one he has not shown during the course of a season before. In other words, this is unprecedented.
Despite throwing the four-seamer as often as he has (sans July), it still is his most effective pitch by a landslide. Sure, it does not get as many whiffs as his breaking or off-speed stuff, but he has held hitters to a .202 average and .274 slugging percentage against the 4-seamer this year. It’s the breaking stuff he has had a very difficult time getting over and, when they have, they have been hit hard.
This brings me back to his lack of four-seamers in July. Why has he shied away from it so much, if it has still been effective? A fastball is also a lot easier to control than a breaking or off-speed pitch, so it is not surprising his July BB/9 is an astonishingly high 8.10.
Also, please look at these Heatmaps, courtesy of Fangraphs, from these two periods. Do you notice anything?
March through May
June through July
In the early months, Kelly was living in the middle of the plate. He did not have any hot, warm or lukewarm zones outside of the strike zone. His command was exquisite. From June forward, though, he has had a problem with his command and the discrepancy between the two heatmaps is evident. Where we saw blue and dark blue outside the strike zone on the left side of the plate in March through May, we now see a bunch of bright colors in the summer months.
He is not locating effectively and it is costing him. Granted, it is hard controlling where a breaking ball goes compared to a fastball. As stated, he is throwing much fewer of the latter.
Even though it appeared Kelly had made a major breakthrough, the season numbers he is posting right now are not too different from his career numbers. Don’t get me wrong, there is definitely a problem with Kelly right now and that’s what we spent the first 700-something words talking about. With that said, this incredible cold stretch has washed out his incredible hot stretch. Kelly has always been a little volatile. Of course, he was never this erratic but he has never featured pristine command in his career. His peripherals literally look almost the same from 2017, a year in which his ERA was south of 3.00.
Joe Kelly seemed like the answer to the Red Sox late-inning bullpen woes just two months ago. Now, there are questions whether he still has a spot on this roster. A phantom DL stint may be looming.
If he can up his fastball usage and mileage, there is a good chance he can iron out some of these issues. The weak contact aspect is concerning but the command has to be the salient problem. Everyone knows there is a better version of Joe Kelly, though. The Red Sox bullpen could use it.