How good was Elieser Hernández in 2020?

On Saturday, Elieser Hernández’s 2020 season officially came to an end after the Marlins transferred him from the 10-day injured list to the 60-day IL (strained right lat). This is a huge blow for the team, though it allows us a head start in evaluating how he did and looking forward to 2021.

After six starts, Hernández was 1-0 with a 3.16 ERA across 25 ²⁄₃ innings. He allowed 21 hits, nine earned runs, and five home runs, besides giving up only five bases on balls and striking out 34 hitters (good for beautiful 1.8 BB/9 and 11.9 K/9 ratios).

But there’s more to fall in love with when you go deeper on his statistics. Several things will tell you that although Hernández doesn’t have overwhelming fastball velocity—91.3 MPH average ranks 26th percentile among MLB pitchers, according to Baseball Savant—he might turn into something very interesting. Even with so much pitching deep in the organization, don’t rule him out as an option for the Marlins rotation in the long run.

For example, his K% has climbed steadily since his MLB debut back in 2018: 15.8% in 2018, 24.1% in 2019, 32.1% in 2020. To give you an idea, Gerrit Cole’s strikeout percentage in his first as a Yankee is 32.9%, not much different than Elieser’s and that says a lot about him. At the same time, his BB% has gone down from 9.5% in 2018 to 4.7% in 2020.

Those ratios will help you a lot especially when you’re a pitcher that gives up more home runs than your team would like (1.75 HR/9, though that got better as well).

Hernández’s slider also deserves a look. It was responsible for 16 of his 34 punchouts and opponents hit a poor .114 BA/.314 SLG off it (4-for-35). This pitch generated a huge 39.3 whiff percentage!

His slider (and mixing it with his low-velo fastball) was the reason he made hitters swing and miss IN the strike zone.

Hernández’s 2020 season has a something that I loved—he didn’t make batters chase as much as last year (28.2% this time), but somehow his contact% lowered for the third campaign in a row (74.3%) and his SwStr% also went higher than ever (13.3%).

Asides home runs, the 25-year-old was really good keeping runners off base, continuing a positive trend.

• 2018: .267 Opp BA, 1.45 WHIP
• 2019: .239 Opp BA, 1.24 WHIP
• 2020: .212 Opp BA, 1.01 WHIP

Two red flags about him could be his stamina and his exit velocity. The former didn’t allow him to beyond 5 ¹⁄₃ frames in none of his six outings in 2020. Besides, he was hit hard from pitch 51 to pitch 75 (.318/.375/.455 slash line). The latter was at 91.8 MPH, a dangerous number when 66.2 % of the balls put in play by your rivals are either a fly ball or a line drive (via Baseball Savant).

But, hey, there’s still room for improvement. And if Hernández can keep this kind of behavior while going longer in his starts, the Marlins can have a great option behind Sandy Alcántara and Sixto Sánchez or even can trade him to cover other areas and, at the same time, give pitching prospects more chances to impress.