Zach Eflin has Changed His Profile
The Phillies best starting pitcher over the past month has been Zach Eflin. This is not the first time Eflin has gone on a dominant run, but he is doing something much different this time, actually striking batters out. Now Eflin has always had pedigree, he was a former 1st round pick traded in a high profile trade, and always rated fairly well as a prospect. He was supposed to have a good changeup, and always showed solid control. Eflin flopped in his first trip to the majors after a hot start, and had offseason knee surgery. He came back with increased velocity in 2017, but still struggled because he had no ways to miss bats.
This year, Eflin is healthy and throwing hard still, but wasn’t really missing bats to begin the year, but then something changed (ignore the last start when he pitched in the rain).
It is rare you see a player throw a pitch slower and have more success, but Eflin had a sharp drop in changeup velocity and then this uptick happened as well.
Eflin’s changeup isn’t moving more laterally and it is only dropping slightly more due to gravity (slower moving pitch taking slightly more time to reach home plate), but what he is doing is throwing it more from the same spot as his fastball and with a bigger change in velocity. This change in velocity has led to more swings and misses and more swings as well. This gives us the biggest change for Eflin, it is his ability to miss bats.
Through his first two years in the majors, Eflin’s top strikeout rate was 12.5%. In the minors he topped out at 20.9% back in AAA in 2016. Eflin is currently at 24.3% in the majors this season. While much of DIPs has been disproven with the idea that pitchers can control the type of contact, the FIP calculation still gives us a rough calculation of the change in profile by striking out more and Eflin is currently running a 2.92 FIP.
Now it isn’t just his changeup, Eflin is throwing harder and elevating his 4 seam fastball more than before to much better results. His slider has gotten harder and sharper and has probably been his best pitch this year, but the changeup really has been a huge bat missing weapon for Eflin. Now Eflin is not become an overpowering strikeout pitcher, but his 24.3% rate this year is 36th among on 121 starters with at least 60 innings. He is not generating as much groundball contact as he used too, and he is running an unsustainably low home run to fly ball rate, so there is probably regression from a sub 3 ERA coming (and Baseball Prospectus’ DRA has him at 4.27). However, he isn’t doing anything totally unsustainable, like when he was striking out no one and throwing complete games, so it is not unreasonable to say that Eflin should at least be a MLB #4 and possibly a #3 going forward. With Nola, Pivetta, and Velasquez, Eflin gives the Phillies at least a nice little nucleus of young starters that doesn’t require deadline retooling.
Graphs from Brooks Baseball