Of all the promising young arms that recorded some time in the big leagues last season for the Marlins, Caleb Smith may have been the best of the bunch. He also went overlooked...until it was too late.
The 27-year old lefty was a pleasant surprise during the first half of 2018. Promising rotation candidates have emerged since his lat injury, but expect Smith to regain his old role in 2019 and legitimize his rookie performance over a larger sample.
How did he get here? Traded from Yankees to Marlins in November 2017 along with Garrett Cooper in exchange for Michael King and international bonus slot money
2018 MLB Stats: 4.19 ERA, 3.96 FIP, 1.24 WHIP, 88 K in 77.1 IP
2019 ZiPS Projection: 4.57 ERA, 4.48 FIP, 1.41 WHIP, 88 K in 88.2 IP
While those overall numbers seem fairly underwhelming, they don’t necessarily reflect how dominant Smith looked at times. To better understand what made him successful last year, and what will enable him to continue that success into the future, we should look at what he does well, and why.
His overall pitch repertoire, in the general sense, is pretty pedestrian—92-95 mph on the four seam fastball, with an average but inconsistent slider, and a changeup that works for him at times but can be rather fringy. Pitch quality data also corroborates this, as his overall 4.35 QOPA (Quality of Pitch Average) was just below the MLB average of 4.50.
However, his 10.24 K/9—which would have ranked 13th among all MLB starters had he qualified—says differently. There’s something about Caleb beyond velocity or plain “stuff” that makes batters uncomfortable.
The first thing to note is that his already above-average fastball plays up due to a very high spin rate of 2,365 RPM. For reference, that places him slightly ahead of household names Luis Severino, Chris Sale, Blake Snell and Jacob DeGrom on the fastball spin rate leaderboard (via Statcast). Those other guys also all possess high-end velocity, which makes their fastballs elite. For Smith, this merely allows him to be successful up in the zone where most pitchers with his type of stuff would usually get knocked around. Working up in the zone with the fastball also allows him to be successful with a fringy changeup that he was still able to get a 17.37% whiff rate on, even though he tends to leave it up in the zone often.
Here’s one example against filthy rich Nolan Arenado of how he uses the changeup off of his fastball to get empty swings. Note how both pitches are in identical locations up and away, only they are 10 mph apart.
This combo was paramount to his success against right-handed hitters, as he only used the changeup 3% of the time against same-sided batters. This contributed to the reverse splits he posted in 2018 (.287 BAA against LHH, .187 against RHH), but also made it critical that he tweak his approach and incorporate more of his slider. That is exactly what he did.
In addition to ditching the changeup against lefties, he used his slider 28.5% of the time last year to the tune of a .154 BAA and a .231 SLG%, easily the best outcome of his three pitches. This also gave him another out pitch to call upon instead of relying too heavily on the fastball.
In order for Caleb to take the next step in 2019, he will have to develop more consistency with his slider. Case in point, let’s compare a good outing from last season with a bad outing, and see what the main differences were:
April 29 vs COL—7 IP, 2 H, 0 ER, 1 BB, 9 SO (good)
According to Brooks Baseball, Caleb had the slider working on this day, with 1.08” of horizontal break, and 1.45” of vertical break, while throwing 70% for strikes, and only one (1) put in play that did not record an out.
April 16 vs NYY—2.1 IP, 5 H, 5 ER, 5 BB, 3 SO (bad)
Fastball and changeup usage remained similar to his start in Colorado, but it was clear that he didn’t have the good slider working in this outing, and the results suffered for it. Only 0.57” horizontal break, 0.89” vertical break, and only 40% thrown for strikes. This allowed hitters to basically eliminate that pitch entirely, only swinging at eight of them, and tee off on his fastball to the tune of 63.5%(!) success on batted balls.
The tools for Smith’s success are clearly at his disposal, but the key to sustaining it will be for him to harness all three of his pitches more consistently, particularly his slider. He is nearly a full return from the lat strain, currently working in simulated games with an eye toward appearing in Grapefruit League games sometime in March (h/t Andre Fernandez, The Athletic).
While there will certainly be tons of competition for rotation spots going forward, if he is able to sustain those adjustments, you could be looking at a key piece to the Marlins pitching staff for years to come.