Jesus Aguilar - Legit Stud Or Destined to Fade?

Every year there are players that show up out of nowhere that have us scratching our heads in amazement. In fantasy baseball, if you're savvy enough to pick up on these newcomers to the scene before anyone else does, you're sitting pretty.

In 2018, that guy has been Milwaukee Brewers first baseman Jesus Aguilar. At the halfway point of the season, he leads the National League with 24 home runs, a .621 slugging percentage, .995 OPS and 160 OPS+. He was named to his first ever All-Star team and also took part in the Home Run Derby, although he was bested in the first round.

So how did a guy that came into the year with 16 career home runs in 337 at-bats over four major league seasons and barely made the roster out of Spring Training turn into such a stud? More importantly, will it last? Let's dive into his profile to see if we can find some answers.

The Early Days

Believe it or not, Aguilar, born in 1990 in Venezuela, signed with the Cleveland Indians as an amateur free agent in November of 2007 and spent his first two years in the Dominican Summer League. He got his first taste of minor league baseball in 2010 and hit only nine homers in 61 games at Rookie Ball and in High A.

2011 was when the power started to show, when he hit a combined 23 home runs with 82 RBI in 126 games between Single-A Lake County and High-A Kinston. He was promoted to Double-A Akron in 2012 and represented Cleveland in the Futures Game alongside shortstop Francisco Lindor.

Aguilar set an Akron record with 105 RBI in 2013 before being called up for his major league debut in May of 2014. However, in his three seasons in the big leagues with the Indians, he played in a total of 35 games and hit .172/.234/.190 with no home runs, five RBI, 21 strikeouts and four walks.

It wasn't until the Brewers claimed him last season that he really started to take off, hitting 16 home runs and driving in 52 runs in 133 games for Milwaukee last season.

Size As An Asset and Weakness

If you aren't familiar with Aguilar at all, it's an understatement to say he's a beast physically. He stands at 6-foot-3, 250 pounds and is certainly intimidating to opposing pitchers in the batter's box.

But while his monstrous stature helps him hit balls well beyond the fences, it also limits him to first base in Milwaukee, a position that was set to be manned by a combination of Eric Thames and Ryan Braun to begin the 2018 season.

It's one of the reasons why, despite hitting 16 home runs with 52 RBI and an .837 OPS in 311 plate appearances in 2017, Aguilar wasn't guaranteed a roster spot out of spring training this year. The fact that the National League also doesn't have a designated hitter didn't help his cause.

But injuries to both Thames and Braun opened the door for Aguilar to become the everyday first baseman since May, and it's safe to say he's embraced that opportunity.

What Has Triggered His Success?

From his early minor league days, it was clear that Aguilar had big league power, culminating in 30 home runs in 2016 at Triple-A Columbus. But what also made Aguilar special then, even if the Indians didn't quite see it, is that he kept his strikeouts relatively low (just under 20 percent) for a slugger of his stature. He was also walking around 10 percent of the time.

He's striking out a little bit more in the big leagues -- 30.2 percent last year and 26.3 percent in 2018 -- but the difference is that Aguilar is hitting the ball really hard and in the air often. He ranks 46th in baseball in average exit velocity (90.5 mph), 35th in hard-hit percentage (44.4) and 33rd in barrels/plate appearance percentage (7.9).

With the StatCast era of baseball in full swing, it gives us a better idea of how well a player elevates the ball. The more often you can elevate a baseball, the more often you're likely to hit for power. Well, Aguilar has certainly improved his launch angle, which has led to an increase in his fly-ball percentage from 37.8 percent last year to 45.4 percent this year. That has led to a career-high 27.0 percent HR/FB rate.

The Venezuelan has also made strides in his plate discipline. So not only is he hitting the ball harder and in the air more, but he's being more selective with what pitches he chooses to swing at. Aguilar is making contact 85.1 percent of the time (a career high in the big leagues) at pitches he chooses to swing at inside the strike zone. That's an elite rate.

Will It Last?

Some skeptics may point to the fact that Aguilar had a .337 BABIP (batting average on balls in play) in 2017 and still hit only .265. However, that was without making the improvements listed above. Players that square the ball up more often tend to have higher career BABIPs.

Aguilar's .331 BABIP this year is similar to what he posted last year, but he's also become a more disciplined hitter and has increased his walk rate from 8.0 percent last year to 10.4 percent and is striking out less (30.2 percent last year compared to 26.3 percent of the time in 2018).

Power is certainly Aguilar's strength, but his improved plate discipline and contact rates are also why you're seeing his average up this year. It also makes it no surprise that he's fourth in baseball in slugging percentage and fifth in OPS behind MVP candidates Mookie Betts, Mike Trout, Jose Ramirez and J.D. Martinez.

It's been that good of a year so far for him, and the numbers show that if he continues with this approach, he should continue to be successful for a Brewers team fighting to win the National League Central.

The 28-year-old slugger has earned his job as the everyday first baseman in Milwaukee and won't be giving that up anytime soon. His performance is a big reason why Milwaukee is contending in the NL, and it's safe to say that the Brewers won't just plug Thames or Braun into the lineup at the expense of Aguilar.

If you were fortunate enough to add Aguilar off the waiver wire in your fantasy league early in the season, you shouldn't be looking to sell high on him just yet. The good times could certainly keep rolling through the second half.

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