Domingo German’s High Velo & Spin Sinker

A few days back, I noticed Domingo German’s fastball velocities and spin rates were unique. Since starting, his sinker (or two-seamer) was faster and had more spin than his four-seam fastball. This setup rarely ever occurs. Pitchers try to get as much velocity and spin as possible on their four-seamer with the intention of generating swings-and-misses up in the strike zone. A sinker usually has less of both to help create sink and the resulting groundballs. Throwing a higher spin sinker than a four-seamer historically is not helpful.

Normally, the other Jeff examines one-offs, but I was dumbfounded when I saw German has this feature. Here the two pitches in action.

Sinker

Four-seamer

After I noticed the anomaly, I asked our pitching guru, Nick Pollack (Pitcher List), if such a pitch mix is possible and he came up blank. Trying to explain the physics behind it is tough as sinker sink because more side spin generated turbulence pushes the ball down.

To find some potential matches I compared all the pitchers since 2015 who StatCast said threw both a four-seamer or sinker (two-seamer) where the spin and velocity on the sinker is more than the four-seamer. I found 32 player and season matches. If I change the query for pitchers who have more spin and velocity on their four-seamer, there are 436 pitcher seasons.

After going through the pitchers, I removed 17 instances of bad pitch classification and found 15 matches.

The average difference isn’t much as it’s about impossible to correctly throw a sinker faster.

The biggest name making meeting the requirement is the 2015 and 2016 versions of Cole Hamels. Over those two seasons, his sinker has 3” more drop and run than his four-seamer. They were two unique pitches with somewhat desirable results.

His sinker generated groundballs with his four-seamer got more flyballs and swinging-strikes. By using my pERA metric, I’m able to get each pitch a grade on the 20 to 80 scale. I removed the 2018 sample (Khul) and the instances when the pitcher dropped the pitch mid-season (Straily).

Overall, this group’s four-seamers were more productive than their sinkers. In only two instances, the four-seamer graded out worse than the sinker.

These results make intuitive sense because pitchers want some separation between their pitches. With the extra spin, these sinkers don’t differentiate themselves enough from their four-seamers and get hit around.

While German’s fastball pairing is unique, it doesn’t make him better. Pitchers can be effective with the pairing as seen with Cole Hamels but that’s it. These pitchers see their sinker perform worse which might allow their four-seamer to play up. It’s tough to tell unless the pitchers’ results could be compared when they did and didn’t throw both pitches. Overall, it’s an interesting finding but I don’t think there is an easy way to know if having a sinker with more spin and velocity than his four-seamer changes a pitcher’s overall value at this point-and-time.