Sonny Gray has been several different pitchers in his career. As a draft prospect coming out of Vanderbilt, the Tennessee native was considered a two-pitch guy (sinking fastball and curveball) whose 5’10 stature and somewhat inconsistent delivery had some projecting a future as a late-inning reliever.
That debate continued until Gray mastered the high minors in the Oakland system. He debuted in the Majors in 2013 and has since made all but nine of his 265 appearances in a starting capacity.
Gray also has more than put to bed his profile as a two-pitch pitcher. Since his debut, his pitch mix and offerings have evolved and changed significantly, which he discussed with FanGraphs’ David Laurila earlier this season, and as this Statcast plot of his pitch type usage illustrates:
If you care to decipher that spiderweb, you’ll see that sometimes he has been primarily four-seamers and curveballs. Other times he has been primarily sinkers and sliders. He’s dabbled with changeups and cutters. He’s tweaked his slider to be more of a sweeper.
Now in his 11th big league season with more than 27 career WAR and a 3.52 ERA / 3.61 FIP, he has demonstrated he is adept at learning and adjusting. The veteran Gray of 2023 throws six different pitch types, five of which he’s thrown at minimum 15% of the time this season. That diverse mix is supporting what has been arguably the best season of his career thus far (2015 and 2019 might be the other contenders). Gray finished the first half with a 2.89 ERA / 2.85 FIP (ranked 10th among all qualified starters) over 99.2 innings pitched and was named to the All-Star Game for the third time.
The Multiple Sonny Grays
Besides Gray’s continual tinkering with his craft, another thing that has held true is that he’s typically been slightly more effective against left-handed batters than right. As you can see in the chart below, it varies from season to season, but he has reversed platoon splits for his career. He’s held lefties to a .285 wOBA, while righties have produced a bit better at .294.
At the career level, that’s a small split, and both numbers are strong relative to the league averages. But, last season, Gray’s first in Minnesota, his 73-point platoon split was the largest of his career. He held lefties to a very strong .243 wOBA allowed but was hurt by his .316 wOBA allowed to right-handed batters. If you look closely at the plot above again, you’ll see that 2022 was the 3rd-year in a row that righties improved their performance against Gray.
Given his ability to spin curveballs and sliders that break away from right-handed bats, which typically is the recipe for dominating same-handed hitters, it’s a little surprising that Gray would be experiencing prolonged troubles with right-handers late in his career.
Working in the Zone
In practice, Gray operates as two different pitchers depending on if he’s facing a left-handed batter or a right-handed batter.
Against left-handers, Gray is primarily a north and south operator, throwing ~86% four-seamers and curveballs, with the occasional slider and changeup mixed in.
Against right-handers, though, Gray works mainly east-west and throws sinkers and sliders/sweepers for ~73% of his pitches. Gray’s preferred fastball for right-handers, while classified as a sinker, is more of a two-seamer, with horizontal, instead of downward movement.
As a result of these two different approaches, Gray works within the confines of the strike zone more often against lefties than he does against righties. The profile and shape of his four-seamer and curveball mean that they look like they are in the strike zone, especially in an east-west sense, all the way from his release to the plate.
That’s less the case with his sinker-slider/sweeper combination, with the breaking balls often starting on Gray’s glove side and moving farther away off the plate and into the left-handed batter’s box. These pitch location heatmap plots from Statcast illustrate what I’m talking about:
You can see in the plot vs. LHB that his locations are stacked in a vertical column within the plate, but that his plot against RHB is more off the plate to his glove side (away from RHB).
Gray threw 51.9% of his 824 pitches against lefties last season in the Statcast strike zone and enjoyed MLB’s highest rate of called strikes (22.0%) among starting pitchers against left-handed batters. About 33% of these offerings were called balls, which was the 144th highest-rate out of 235 pitchers on the list.
By contrast, 44.1% of his 1,048 pitches to right-handed batters were mapped in the Statcast strike zone. 38.1% of them were called balls, the 15th-highest rate of called balls to right-handers among 255 starting pitchers on the list.
Gray’s success against right-handed batters relies heavily on getting them to chase and swing and miss at sliders out of the strike zone. For whatever reason, last season, batters did not do that as much.
His overall swing and miss rate against right-handers dropped to 23.9% when it had been 27.3% previously. Similarly, his swing and miss rate when righties chased out of the zone fell to 34.4% from nearly 49% the season before. Right-handed hitters were able to do a better job laying off Gray’s tempting pitches and, as a result, more than half of his sliders/sweepers to right-handed batters went for called balls. That’s how those offerings went from allowing .200 wOBA and -1.4 run value in 2021 to .279 wOBA and +5.0 run value last season. Those called balls, perhaps more than anything else, drove his wide reverse splits last season.
Bridging the Gap with Cut
This season, through the first half, Gray has flipped his splits, holding righties to a much stronger .276 wOBA and lefties to a .289 mark that is right in line with his career average. Much of that is due to the fact that the swings and misses from righties have returned in a big way. He’s pushed his overall swing and miss rate against right-handed opponents to 32.6% and his whiff rate when righties chase up to a whopping 61.6%. His called ball rate with his sweeper is down to 41.4%.
Gray evolved again, as he always has. This time he’s added a cut-fastball that he’s used prominently against right-handed batters, something that he was open about wanting to do in spring training and that I briefly wrote about in an early season off-day notes piece.
Sonny Gray said he's working on a new — or as he called it, "new-ish" — cutter, thrown harder.— Aaron Gleeman (@AaronGleeman) March 3, 2023
He used it on 5 of 38 pitches today, averaging 87.9 mph, compared to 83.4 mph last season.
He threw only 9% cutters in 2022, almost solely to right-handed hitters. Something to watch.
Gray has thrown his new cutter 21.4% of the time against right-handed batters, cutting into both his sinker and slider usage. Whereas nearly three-quarters of his pitches to righties last season were sinkers and sliders, now only about half are. Three-quarters are now made up of the sinker-cutter-slider combination.
Research about pitch tunneling from Ethan Rendon, Elijah Emery, Will Sugar, and Tieran Alexander writing at ProspectsLive last fall put some numbers to the optimal pitch shapes for tunneling and how to make life more difficult for hitters.
Regarding the pairing of fastballs and sliders, they found that 6 to 14 inches of horizontal movement separation and 8 to 16 inches of induced vertical break separation are optimal. Gray’s sinker and sweeper are separated by nearly 30 inches horizontally and about 16 inches vertically.
With differentials that wide, and Gray’s propensity to throw the pitches out of the zone, he clearly needed something in between the two to add deception to his whole arsenal against right-handed batters. His new cutter, which runs 87.6 mph on average and with about 6 inches of horizontal and 10 inches of induced vertical movement, is the perfect addition to bridge the gap. That’s illustrated well by overlaying Gray’s pitch movement plots:
Instead of changing his sinker and sweeper to look more like each other, the cutter adds an element that looks like them both, and makes his whole arsenal more contiguous. As the writers from ProspectsLive put it, “the fastball and slider don’t have to look the same, they just have to look like the cutter, which looks like both of them.”
As a result, Gray is throwing a few more (46.0%) of his pitches to right-handers in the zone and his location heatmap shows his pitches are more threatening to the strike zone:
Not only has Gray’s cutter enhanced his existing arsenal, but the pitch is very good on its own. So far this season, batters have hit just .234 and slugged .304 against it. It’s accumulated a -5 run value at a rate of -2.1 per 100 pitches. That ranks as the 15th-most productive cutter in all of baseball. Not bad for a new offering.
The pitch has closed his gap with righties and it’s had positive benefits for his arsenal against lefties, as well. FanGraphs’ Estaban Rivera detailed this well, with several GIFs illustrating how Gray’s arsenal tunnels together, a few weeks ago. Gray only throws the cutter 8% of the time against left-handed hitters, but the pitch has racked up a -1.2 run value in that small sample.
At the same time, Gray’s embrace of cut has also impacted his four-seamer, which now features a little bit of the illusion of cut. Last season Gray’s four-seamer had about 1.5 inches of arm-side run, but this season that has changed to almost 0. That absence of arm-side run can be perceived as cut by hitters, who almost always see four-seamers with arm-side movement. This improved shape, which Gray has said is natural for him, serves to improve his four-seamer’s tunnel with his signature curveball which has drawn whiffs on 31.4% of swings against it this season, compared to 24.3% last year.
That Gray is an artist comes through in all this data, but also in the way he talks about what he does. He sat down with Rob Friedman (Pitching Ninja) for almost an hour earlier this season and talked in depth about how he thinks about his pitches and what is behind the adjustments he has made, including the addition of his cutter. I highly recommend checking out that interview for anyone curious to learn more about pitching shapes, grips, and pitchers’ mindsets. In the meantime, let’s enjoy watching Sonny continue to master his craft.