CC Sabathia has had a poor time over the last few seasons, but things could get a lot worse for him soon. This week MLB has been discussing the possibility of raising the strike zone in order to correct the ongoing trend of low strikes and help stimulate offense around the league. Pitchers take advantage of this trend, and even helped to cause it, by throwing borderline strikes at the knees that most hitters can't even come in contact with. While raising the zone might be fair to the hitters, it will prove to be extremely unhelpful to Sabathia as he tries to have a successful 2016 season.
August Fagerstrom of Fangraphs covered the declining strike zone and the pitchers that have benefitted the most from low strikes. He visualized the pitchers into a list of highest percentage in the lower part of the zone and the highest called strike percentage in the lower part of the zone. Masahiro Tanaka made the list for highest pitch percentage, but not strike percentage because a lot of his low pitches are swinging strikes. The only other Yankees who made either list was CC Sabathia, and he made both, meaning he benefitted from the umpire's low strike zone more than any other pitcher on the team and more than most in the league:
It's easy to see from this comparison of CC Sabathia's heatmap by pitch percentage (on the left) that he pitches much more often in the lower part of the zone than the rest of MLB (on the right). That likely comes down to the fact that his 22.2% usage of sliders is among the top 20 in baseball among qualified pitchers and he's also only one of almost 20 who even used the sinker in 2015. A raised strike zone would not be kind to him:
You can see that, from the black box i placed to represent the strike zone, Sabathia was helped a lot by low strikes in 2015. Among his repertoire of pitches are a sinker, which is designed to induce ground balls, a slider, which drops down through the zone, and even a four-seam fastball that created a lot of low strikes last year. Most of his arsenal is aimed at trying to get knee-high strikes, especially now that his velocity has dropped and he'd be more likely to (try to) stay away from the upper part of the zone, but a new strike zone could complicate things.
The proposed strike zone would place the bottom of the zone above the knee, rather than below the knee. Suddenly, sliders that were once borderline pitches are balls and if CC has to adjust, he could end up elevating a 90 mph fastball right into the heart of the strike zone. He's already had trouble with home runs over the last few years with home run/fly ball rates routinely in the teens, so just imagine what things would be like if he was forced to pitch a little higher over the plate.
Now, this is not exactly scientific, but if you go by the thought that the zone should be the letters of the jersey to the knees, moving it to the top of the knees would eliminate a good part of the bottom of the zone. The blue box I made should tell you just how drastically different things would be for CC Sabathia if he had to deal with a new strike zone. That's a whole lot of strikes that are now borderline calls and borderline calls that are now balls.
CC has very few things going for him at this point in his career. In 2015, he was among the top 20 in contact rate on pitches in the zone (89.2%) and bottom 30 in swinging strikes (9.1%). That's a pretty ugly combination, but some late-season success, back by absolutely none of his peripherals, elevated him to a 3.63 ERA in the second-half. At least he has that to hang his hat on. Unfortunately, bringing the zone up to above the knee would all but seal his fate.