Checking in on Zach Eflin
It’s been an up and down beginning to Zach Eflin‘s major league career — or, more precisely, a down and up beginning. His major league debut went about as poorly as a debut can go. He struck out the first batter (yay!), but from there it unraveled in almost historic proportions. His line that day: 2.2 IP, 9 H, 9 R, 8 ER, 3 BB, 2 K, 3 HR. It amounted to a game score of 5 which is the lowest game score in a debut since someone named Arnie Munoz posted a -7 game score for the White Sox in his 2004 debut. Here’s a list of the most recent pitchers to post a game score that low in their debut:
That’s, uh, not a terribly encouraging group of names for Eflin to join. Munoz never started another major league game while Stephens and Busby combined for 21 more starts in their careers. And, yet, Eflin has followed up this thoroughly inauspicious start with a remarkably promising run of five successful starts.
|Next Five Starts||32.2||28||10||8||3||16||2||0||2.24||0.96|
Eflin has equaled his earned run and walk totals from his debut in his last five starts combined. He’s also allowed fewer home runs during that stretch! It’s a tremendous turn around worthy a bit of investigation. Was his first start just the result of nerves getting the best of him? Is he really as good as he’s shown in his most recent starts?
I know you’re supposed to lead with the bad news, but when a pitcher is putting up results as strong as Eflin’s, it seems ridiculous to begin by dwelling on the negative. Eflin has been really impressive! He’s limited the opposition to three runs or fewer in each of his last five starts and even threw a 92-pitch complete game — sure, it was against the Braves, but a complete game is a complete game.
The best thing about Eflin and the thing that gives me the most hope for the future is this: the guy throws strikes. He faced 128 batters in those strong last five outings and walked just three. That amounts to a 2.3 BB% which is just a hair above the absurd 2.0 BB% Clayton Kershaw has posted this season. Take a look at his pitch heat map to date:
That’s a ton of blue on the edges of the zone. The only areas where a bit of pink shows up is middle out to left-handers which is where his changeup has been hanging out and down and away to righties which is where he occasionally buries a slider. Beyond that, he’s consistently staying in the zone.
The other really encouraging thing is that he’s not just throwing strikes, he’s doing so with good velocity. According to BrooksBaseball, Eflin is averaging 92-94 mph with his fastball and has touched 97 mph. These are good things!
Throwing strikes is good. Throwing strikes batters can’t hit is better and, so far, Eflin is not doing that. Opponents have posted an 86.4% contact-rate against him. That contact-rate would be the second highest among qualified starters were he qualified. The only pitcher with a higher mark: the enigmatic superhero, Bartolo Colon (88.6%). Colon may be proving that there is a successful path forward for contact-oriented pitchers, but he’s more of an exception than an example for Eflin to model himself after.
This high contact-rate means that, despite the fact that Eflin keeps the ball in the zone, his strikeout rate is dismal. He has struck out just 12.1% of batters — a mark which would rank third worst among qualified starters behind Mike Pelfrey (10.4%) and Martin Perez (11.3%). It’s great that Eflin doesn’t yield walks, but if he can’t miss bats, then his outcomes are going to be deeply tied to quality of contact and team defense. Again, this is a path that can have success, but I worry that an overreliance on BABIP could open him up to inconsistent performance from start to start.
What To Watch Going Forward
A strike-thrower who pitches to contact isn’t the sexiest profile a starting pitcher can have, but it’s a reasonable enough starting point. Eflin looks like a guy right now who can stick in the major league rotation for the remainder of the year and that’s great! One thing I haven’t mentioned yet is that he’s just turned 22 in April. That’s ridiculously young and it provides hope that there’s still room for Eflin to keep developing and improving. Perhaps he can further refine his slider and changeup into pitches which are more consistently able to induce whiffs. Strikeouts ticking up and contact ticking down is an adjustment that certainly could happen in Eflin’s future. That’s more of a long term project than a quick fix, however, so for right now I’m going to be watching Eflin for something else: pitch location.
Yes, Eflin throws strikes, but he only throws certain kinds of strikes. So far, he has shown himself to have a very clear plan at the plate. Against right-handed opponents, he’s a fastball/slider guy. As a result, his pitch chart looks like this:
If you’re a right-handed batter stepping in against Eflin, it’s more likely than not that you’re going to get a fastball up in the zone or a slider breaking away from you. I’d like to see Eflin expand his zone, whether that’s by peppering the bottom of the zone with curveballs more consistently or better locating his fastball to the edges of the zone.
It’s a similar story for Eflin against left-handed batters, although his repertoire is a bit more mixed. He primarily uses his four-seamer, sinker and changeup, but will also mix in his slider. The chart:
He is living on the outer edge to lefties. It’s an approach that makes sense given that both his sinker and changeup have a great deal of arm-side run which will allows him to run those pitches away from the hitter. However, there’s not a lot of balance in his usage of the zone. To righties and lefties alike, Eflin would do well to keep them honest by establishing his ability to command the inside part of the plate. I worry that Eflin will allow batters to get comfortable and focus in on a single area of the zone rather than keep them guessing through varied pitch selection and location.
After the disastrous debut, it’s been wonderful to see Eflin find a bit of success. He’s not yet a finished product, so it’s hard to say definitively exactly what type of pitcher he’ll end up being. Even if he never ends up being anything more than a back-of-the-rotation pitcher, he still has very real value for the Phillies right now. Barring any unforeseen struggles, I expect that he’ll get plenty of time in the second half to continue refining his craft at the major league level. On days when the BABIP Gods smile on him, he may look phenomenal. On days when they don’t, bloops and dinks may sink him in frustrating fashion.