With a .429/.500/.667 slash line against, it isn’t a surprise that Chris Stratton’s 84.9 mph changeup was his least-used pitch in 2019 at just 6.75%. Of the 74 he threw, 24 ended the at-bat with nine resulting in a hit, three in a walk, and three in a strikeout. When thrown in the zone, the changeup had a .375 BAA, but when thrown outside the zone, hitters tagged it to a .750 BAA, indicating they were able to resist flailing at the pitch and taking it for a ball. When they did swing at it, they made good contact.
As Stratton’s secondary secondary pitch at just 12.5% usage, the curveball had similar results to his slider despite the reduced usage. The slider had 16 strikeouts and two home runs allowed (in 303 thrown), but the curveball allowed three home runs and grabbed 15 strikeouts in just 157 thrown. Hitters whiffed 14% of the time when swinging at the curveball, but they also hit it hard (.500 SLG and .250 ISO). Stratton threw the pitch in the zone just 38.9% of the time, but batters had a 96.7 Z-Contact%. When he was able to keep the pitch outside the zone, it had a 38.5% O-Swing and a 43.2% O-Contact.
The fastball was Chris Stratton’s most-thrown pitch with 56.9% usage, but hitters had a 127 wRC+ against it. The pitch allowed a .289/.369/.451 slash line, with Statton getting into trouble with an 11.9% BB rate and a 12.6% K rate. Averaging 92.5 mph and topping out at 96.2 mph, the fastball had an 8.2% swinging-strike rate, but had an even-ish batted ball distribution with 30.9% LD, 35.5% GB, and 33.6% FB.
The slider was Stratton’s second-most used pitch (23.8%), and it was his ground ball pitch. Of the contact made on the slider, 53.1% resulted in a ground ball, with the pitch generating just a 26.6% line-drive rate and a 20.3% fly-ball rate. The pitch had a 38.1% O-Swing and a 14.5% swinging-strike rate, but only garnered 16 of Stratton’s 69 strikeouts on the season. He did allow two home runs on the slider and a .313/.345/.475 slash against, which made for a 125 wRC+, but the slider was effective in limiting damage.
Stratton pounded the zone with his four-seam fastball (57.8 zone%), and it produced great results, racking up a 9.9 pVal in 1,375 pitches. While his 6.1 K-BB% isn’t impressive on the surface, it was the third year in a row of improvement in that area, which might be a great sign of continued growth. Movement-wise, the four-seamer has a nice, tight loop to it, which might help explain some of the poor fly-ball contact it elicited (30.1 FB%, 21.6 IFFB%).
Stratton’s big, looping 12-6 curveball has normally been a great pitch, as hitters put up negative wRC+ values in 2016 and 2017, but it didn’t fare nearly as well in 2018 (-5.8 pVal). It appears that a decent chunk of those outcomes might be BABIP-related, as the pitch’s 2018 .340 BABIP represented a 148-point jump from the pitch’s previous high.
Stratton’s slider saw major regression from a lot of its underlying statistics in 2018, including swinging-strike rate (down to 11.3% from 16.1%), K rate (down to 21.7% from 33.3%), and velocity (down 0.5 mph on average to 83.5). This handed hitters much greater success against the slider in 2018—to the tune of a .280 BAA, .173 ISO, and a 118 wRC+.
Thrown 248 times in 2018, Stratton’s changeup got hit hard to the tune of a .303 BAA, .288 ISO, and a 150 wRC+. Despite the high ground-ball rate (57.1%), Stratton’s changeup struggled with a HR/FB% of 41.7%. There were some encouraging signs, as Stratton more than doubled his K rate to 13.4% and cut his walk percentage to 1.5, but he’s going to have to figure out how to keep the pitch in the yard if he wants it to be useful.
Stratton’s sinker accomplished its primary objective of generating ground balls and limiting home runs (53.1 GB%, 0.0 HR/FB%). Unfortunately, when it was hit in the air, those batted balls manifested themselves in the form of line drives (31.3 LD%), which led to a .424 average and a 199 wRC+. Combine that with a -10.8 K-BB% ratio, and you have a pretty good idea why this pitch struggled in 2018.