Jesús Aguilar: Fishy or For Real?

It looks like the Marlins hit it right on the dot by bringing Jesús Aguilar into their clubhouse. The right-handed power hitter has done nothing else but rake in Miami’s first 11 games. After Aguilar’s subpar 2019 season, the Marlins were skeptical about who they really acquired during the offseason—there was a world a difference between Aguilar’s glorious 2018 season where he hit 35 home runs with a 134 wRC+, and his below-average 2019 where he posted a .714 OPS (.176 points lower than in 2018).

After a scorching start at the plate, Miami is hopeful the Venezuelan first baseman is back to his 2018 ways. But the question remains...is this start Fishy or For Real?

There are 3 factors that have caught my eye regarding Aguilar’s struggles/success.

1) Fly balls are better than ground balls

Aguilar had a breakout year in 2018, where he slashed .274/.352/.539 and had an fWAR of 3.1. He was regarded one of the best power hitters that season, and a lot of that is due to his launch angle. In 2018, Aguilar had a 16.2 average launch angle, which was in the top 30 among MLB qualifiers. Compared to 2019, Aguilar’s launch angle decreased by 2.6 degrees, which played a huge factor in Jesús’ decrease of power that season.

In 2018, Aguilar hit a home run, on average, every 16 plate appearances while in 2019, he averaged a homer every 30.75 PA. With a much lower launch angle, not only does the production of home runs decrease but the ground balls increase. Take a look at Aguilar’s GB% in his career:

The GB% increase in 2019 is substantial, as it rose up by 6.7% from the prior season. Aguilar has controlled the ground balls better in 2020, most of it due to his increased average launch angle. He is creating that angle with a less upright batting stance, as fantasy analyst Mike Kurland illustrates.

@Mike_Kurland/Twitter

Through 11 games this season, Aguilar is averaging a launch angle of 18.6 degrees.

2) “Staying true to his game”

The easiest way to explain Aguilar’s early success is because he stayed true to himself. He understands he is a power hitter who can create havoc when he pulls the ball, and that is exactly what he has done in 2020.

In 2018, Aguilar had a pull% of 43.5% and hit 20 of his 35 home runs to left field, however, Aguilar had a pull% of 37.1% in 2019, hitting only 5 of his 12 home runs to left field. He was seemingly trying to hit the ball to all fields. While traditional hitting coaches may applaud that change in approach, it backfired for Aguilar.

Pulling the ball will be a key factor for Aguilar to replicate his 2018 success in 2020.

3) Say no to High Heat (sorry, Mad Dog)

Out of Aguilar’s 35 home runs during his breakout campaign, 20 came off fastballs, 12 off breaking balls, and 3 off off-speed pitches. In 2019, however, Aguilar only took 6 fastballs for home runs, a huge drop-off.

Why did this happen? Were pitchers attacking him with more breaking stuff?

Surprisingly, this was not the case. Besides a slight increase in off-speed pitches thrown to Aguilar, the rest stayed pretty constant in 2019 from his 2018 season. Take a look for yourself:

So, if the pitchers were throwing him roughly the same proportions of pitches, what happened? Well, let me show you. This is what Aguilar’s swing % in 2018 and 2019 looked like on fastballs:

From these two graphs, we can see that Jesús was swinging at the high fastball way more often. But it’s equally important to understand how opponents were attacking him.

Take a look at the locations where pitchers threw fastballs to Aguilar in 2018 and 2019:

From what it looks like, Aguilar was thrown fastballs, on average, to the same locations in 2018 as in 2019. For some reason he was swinging way more at the high heat in 2019. Whether those high-fastball swings were difficult to barrel, caused more ground balls, or made him whiff more, Aguilar was unable to produce against them in 2019.

As of now, in 2020, Aguilar has retreated to swinging at middle of the zone fastballs, which could also be an indicator of his recent success. This is his fastball swing% in 2020:

As long as Aguilar does not leave his comfort zone to swing at too many high fastballs, he should keep his good streak going. He must go after pitches that suit his swing path and continue to pull the ball as much as he does.

After adding Jesús Aguilar on a measly waiver claim, the Marlins are getting the absolute best version of him. Initially viewed as a stopgap at first base, Aguilar will have some unexpected staying power on the roster if he sustains this level of performance.