Getting the Most Out of Robbie Erlin

Free agent left-hander Robbie Erlin threw 55.1 innings across 37 appearances in a mediocre 2019 campaign. He gave up a lot of hard contact (43.7%), posted a 5.37 ERA, and saw his walk rate balloon to almost three free passes per nine innings. Erlin’s WHIP also skyrocketed from 1.14 in 2018 to 1.57 last year.

We can’t ignore that some bad luck may have found him; his BABIP was .373, almost 60 points higher than his career norm. That, coupled with the big jump in walk rate (2.7% to 6.0%), put Erlin in a lot of bad situations. Although he did manage to post a 3.61 FIP, that doesn’t sound like a pitcher destined for an especially promising 2020 season, if he’s picked up at all. So what value can be drawn from Erlin?

Well, for starters, Erlin mixes his pitches really well. The ability to keep hitters on their toes is advantageous regardless of how good your stuff is. In Erlin’s case, his stuff needs to be good, and there are ways in which he can make that happen.

Let’s first take a glance at Erlin’s five-pitch arsenal: a two- and four-seamer, a slider that is sometimes mistaken for a cutter, a curveball, and a changeup:

Erlin has experience as a starter and a reliever, and without knowing how teams would deploy him the most, accommodations will need to be made for both situations. Given his issues with command last year, I’d recommend focusing on two (maybe three) pitches as a reliever and three as a starter with possibly a circumstantial fourth option.

Let’s dig a little deeper into each pitch and see what Erlin is working with.

Erlin’s four-seamer was thrown at below-average velocity (91.0 mph) with an above-average spin rate (2320 rpm). The pitch was beaten up pretty badly last year, as hitters produced a .403 wOBA and a 7.12 xFIP against it. Erlin kept the pitch low in the zone, and we know that throwing fastballs low in the strike zone tends to cause a lot of problems for pitchers.

His ill-advised location was only part of the story. Using Driveline Baseball’s Bauer Units, Erlin produced a score of 25.5, which means he should be keeping the pitch up in the zone. His zone batting average chart would agree.

Erlin produces some decent rise with his four-seamer with some slight arm-side movement; all the more reason to keep it elevated. When Erlin delivers the pitch middle/low in the zone, he creates a straight(ish) offering that hitters can tee off on, and they did just that according to Alex Chamberlain’s Pitch Leaderboard chart which shows a 13.3% barrel rate.

Erlin’s curveball has been his most consistent pitch in terms of performance and produced the best results of any pitch he threw in 2019. It yielded the lowest exit velocity, permitted a FIP of just 0.84, and struck out hitters at a rate of 32.6%. It has some major drop and over half of all contact on the pitch resulted in weakly hit groundballs.

Erlin’s third-most-used pitch last year was his two-seamer. Its shape has a bit more run and depth than his four-seamer, though both are thrown with the same velocity. Erlin’s two-seamer was nothing more than an average pitch, as evidenced by the 5% swinging strike rate. Generally speaking, the pitch doesn’t seem to do enough to differentiate itself from the four-seamer.

This being the case, it isn’t necessary for Erlin to continue using the two-seam fastball as it creates superfluity in his repertoire, especially when taking the changeup into consideration.

For the changeup, it has the makings of an out pitch (22% SwStr rate) but Erlin struggled to command it in 2019. He issued a lot of walks with the changeup, and when he had to locate, he was burned quite a bit (22.2% HR/FB rate). Despite the ugly facets of the offering, the pitch shape he creates produces a bona fide two-plane break. If he can get the pitch back under control, it has the potential to be a great weapon.

Lastly, Erlin’s slider/cutter was his least-used pitch last year. Its deployment rate is curious, given almost 75% of contact on the pitch was considered weak (81 mph average exit velocity). That’s not to say it’s a given that the pitch is a diamond in the rough. It’s possible that since hitters rarely saw it, they weren’t able to attack it efficiently. As with the changeup, he struggled with its command, allowing a lot of home runs with the slider for how little it was thrown.

All that said, we have two or three good pitches for Erlin to work with. Despite how weak they all came off last year, there are options to alleviate their debilitation.

When you look at Erlin’s curveball, one of his better pitches, it pairs really well with his four-seamer. However, this is mostly contingent upon Erlin keeping his fastball up in the zone when he wants to play them off each other.

There is a 15-mph difference between both pitches, which can help offset the lack of four-seam velocity. More importantly, we have another case of ideal spin mirroring given the gyro tilt and spin direction that allow both pitches to counteract each other.

So now that we know the four-seamer and curve are keepers, the next task will be getting his changeup under control. The pitch shape is good and can play off of the vertical spread of the four-seam and curveball by breaking off at a 45-degree angle. As mentioned earlier, the changeup wasn’t without issues; Erlin threw the pitch in the strike zone just 28.1% of the time. Without evidence pointing to whether Erlin wanted to keep the pitch out of the zone that much, there might be something else at play, here.

Erlin dropped his changeup release point several inches vertically, which also forced his arm to reach out a tad further horizontally. His 2018 release point resulted in about twice as many changeups hitting the zone which, in turn, saw much better results.

By raising his release point a few inches higher and making a slight adjustment on its gyro orientation, we can see the pitch might be able to hit the zone a bit more accurately than it was able to in 2019. The two variations don’t behave all that differently, but those few inches can be the difference between a called ball and strike.

In fact, it wasn’t just the changeup release that was different; all of his pitches saw lower release points in 2019. Is it possible that this is correlated to his lackluster performance last year?

If nothing else, Erlin should raise his changeup release point to better play off the four-seam and curve. The curve has done well on its own, regardless of arm slot, and raising the four-seam release point may not be necessary, either. The ability to keep the pitch high in the zone is more a feature of command than a byproduct of release points.

Here’s a look at Erlin’s 2019 fastball and curveball release points along with the suggested design of his changeup.

A refined four-seam and curve, with a dash of changeups, could be strong enough to carry Erlin during any bullpen stints that might be required. If teams will use him as a starter, he may want to toss in the slider/cutter from time to time in order to give his arsenal a pitch that cuts as opposed to the run that comes with his fastball and changeup.

His 2019 notwithstanding, Erlin hasn’t done much to make teams take a serious look at him this offseason. However, I see the potential for a valuable pitcher in Erlin. He certainly isn’t a lost cause; there are some command issues that need to be addressed, and perhaps spending some time in the minor leagues to get it right is in order. With these suggested pitch adjustments, their usage, and how he deploys his arsenal, Erlin could end up being a free agent steal in 2020.