The 180 that Patrick Corbin has gone through as a pitcher can only be described in one word: ugly. He’s gone from three shutout innings in Game 7 of the World Series to now statistically one of the worst pitchers in the league over the last two seasons.
Unfortunately for the Nationals, Corbin is their ace and he has not pitched like one this season. Through his first two starts of the season Corbin has pitched only 6.2 innings, struck out 7, walked 5, allowed 14 hits and has given up 8 earned runs. That’s a 10.80 ERA and a 2.85 WHIP.
On Opening Day against the Mets, Corbin struggled and when you look at the advanced metrics you can see the red flag. His velocity was down from his career average: Fastball -1.4 MPH, slider -0.8 MPH, sinker -1.1 MPH. His spin rate was down as well: Fastball -50 RPM, slider -38 RPM and sink -42 RPM. His slider’s vertical and horizontal movement was down as well. Now, it was rainy and cold so I didn’t look too much into this.
In last night’s start Corbin’s pitch velocity was up from his average velocity (slider was 0.5 mph above average, highest amongst his pitches). His spin rate was up amongst all pitches (changeup had 85 RPM more than average highest amongst all). Why did he get rocked if velocity and spin rate were consistent? The issue was his pitch movement. His vertical and horizontal movement on the slider was 2 inches below his normal break.
Corbin is a healthy pitcher, and at only 32 years old, guys at this age don’t suddenly lose their talent without a massive injury. There were concerns that his 2018 season in Arizona was an outlier, but even so, the season he had in 2021 and so far this season are far worse than anything he’s done. So why all of a sudden is he not an effective pitcher? The answer to me is his release point.
I watched three random games that Corbin started. From left to right below, the first picture is from 2019, the second from 2021 and the third is from last night. Notice how in 2019 Corbin had a ¾ release point versus 2021 and last night when he displayed a very high release point.
Why is it so important to note the drastic change in Corbin’s release point? If Corbin is having a higher release point for his slider only that makes it that much easier for the opposing team to know what pitch is coming and having a greater chance of making contact. A higher release point also completely changes the pitch axis which directly changes the movement on a slider and prevents a sinker from sinking.
In a Fangraphs study of every single pitcher in baseball, they found that those with a consistent release point had an average ERA of 2.95. Pitchers who had even just one inconsistent release point in their pitch arsenal had an average ERA of 3.69. The study also found that there was a direct correlation between swing and misses, pitch movement and release point consistency.
Corbin is a slider pitcher and relies on the swing and miss and opposing hitters chasing out of the zone. Look at the drop in his K%. In 2019 it was 28.5%, in 2021 it was 19%, and this season it’s 18.4%. In that same time frame, Corbin’s outside zone swing % has dropped every year from 2019 and his hard hit % has gone up.
Publicly, the Nationals are saying that Corbin’s workload in 2019 is why he is struggling. We all need to hope that internally they are working on fixing his release point or it is going to be a long, long season.