Praise and glory for the almighty Jesus Aguilar

Jesus Aguilar wasn’t going to get a fair shake with the Cleveland Indians, the organization that he originally signed with as an international free agent on November 13th, 2007. He had gotten a few cups of coffee with the Tribe during the 2014-16 seasons, but was stuck behind Carlos Santana on the first base depth chart and then was even further blocked from regular big league time when Cleveland inked Edwin Encarnacion to a multiyear deal to be the designated hitter. Out of minor league options and seeing the writing on the wall, Aguilar asked the organization to try and find him a different opportunity with more of a chance at big league at-bats. They obliged his request, and on February 2nd, 2017, the Milwaukee Brewers were awarded a waiver claim for the lumbering first baseman.

At first blush, the transaction seemed a little curious. Milwaukee had inked Eric Thames to a multiyear deal to return from Korea just a couple months before to serve as the primary first baseman. Aguilar was a good hitter in the minors, but not a great one; his .818 OPS in three seasons at AAA didn’t jump off the page, although he did hit 68 home runs during those years (including 30 in 2016). He was also considered strictly a first baseman, and even by that time we had learned how highly Slingin’ David Stearns and company value positional versatility. It seemed like it would take a lot for Aguilar to make the squad, and even then it wouldn’t be in a significant role as Thames’ backup/right-handed hitting platoon partner.

Jesus wound up tearing the cover off the ball that spring and made the Opening Day roster in a decision that essentially boiled down to him versus Scooter Gennett. He endured a three-week long hitless streak in the early part of the season but eventually settled in and received semi-regular playing time at first base and was the team’s top pinch-hitting option. At the end of the season, his numbers appeared solid enough: a .265/.331/.505 slash for a 112 wRC+ and 16 home runs in 331 plate appearances. In the broader context of the league, the numbers Aguilar put up were right on par with a league-average first baseman.

But Aguilar’s peripheral numbers were a bit precarious. He struck out in 30.2% of his plate appearances and his .265 batting average appeared bloated by a .337 BABIP. His swing-and-miss rate of 14.5% was one of the higher marks in the league. His numbers felt ripe for some regression heading into 2018. When the Brewers added Christian Yelich and Lorenzo Cain to the fold over the winter and announced that Ryan Braun would start seeing time at first base, Aguilar appeared to be the odd man out. He headed into Spring Training 2018 needing to battle for a job once again in camp.

The Brewers found a way to keep Aguilar in the fold again once Opening Day arrived, and early season injuries to Christian Yelich, Eric Thames, and Ryan Braun eventually led to Jesus getting the opportunity to play most everyday at first base. And he used that opportunity to do something that not many 28 year old waiver claim first baseman have - improve his game and seize a role.

Perhaps the biggest difference in Aguilar from last season to this one has been his success against four-seam fastballs. Last year, he hit .250 against four-seamers with six home runs, but he also whiffed 28.1% of the time he swung at a fastball and struck out on the pitch 38 times. According to the linear weights from Pitch Info, Aguilar was worth -1.3 runs against four-seamers for the season. Fastballs up in the zone were a problem for Aguilar, as he hit just .111 against high heaters. But he just couldn’t stop offering at them:

In 2018, however, Aguilar is crushing four-seam fastballs. He’s hitting .367 with a .684 slugging percentage against opposing pitchers’ heat, including crushing seven of them for dingers. Pitch Info has his value against four-seamers rated at +9.6 runs already on the season. He’s slashed his whiff per swing rate against fastballs by some seven percent, in no small part because he’s stopped flailing away at high heat and focusing most of his attention on the fastballs he can do damage on, the ones belt high and out over the plate:

On the whole this season, Aguilar is actually swinging at a slightly higher percentage of pitches out of the strike zone. But he’s become much more disciplined within the zone and seems to have vastly improved his bat-to-ball skills. Jesus’ zone swing percentage has dropped three points down to 60.1% this season, but his contact rate on pitches he swings at inside the zone has jumped up some seven points to 86.3%, which is now comfortably above the major league average. As a result, Aguilar’s swinging strike rate has fallen by two percent and his overall strikeout rate is down to 25.3%, while he’s simultaneously boosted his walk rate from 8% to 9.3%.

Aguilar has cut his greatly reduced his strikeout rate without sacrificing any of his power at all. He constantly hits the ball on a rope, with his 46.4% hard contact rate ranking 14th in the league (min 200 PA). It’s even an improvement over last year’s ridiculous 45.2% mark, and when you hit the ball that hard that consistently over a long period of time, it’s easier to justify 2017's .337 BABIP and this season’s .333 mark. Jesus hardly ever hits the ball on the ground anymore (29.4%), and the copious amounts of hard-hit line drives (24.2%) and fly balls (46.4%) he’s producing are generating big results.

Yesterday afternoon, Aguilar hit his 18th home run of the season, this one against the Kansas City Royals. On Friday, he single-handedly provided the Brewers all the offense they needed against the St. Louis Cardinals, breaking up Jack Flaherty’s no-hitter with a solo home run to tie the game at one in the 7th inning and then walking things off in the bottom of the 9th with another solo shot. For the 2018 season, Zeus now owns a .304/.367/.628 slash for a .995 OPS and 160 wRC+. His 237 plate appearances aren’t yet enough to qualify for the batting title, but lower the parameters to 200 plate appearances and here’s where he ranks among MLB first baseman:

160 wRC+: 2nd
.995 OPS: 2nd
.324 ISO: 2nd
18 HR: t-1st
.628 SLG: 1st
2.4 fWAR: t-5th
+1.4 UZR: t-10th
237 PA: t-26th

Jesus Aguilar has now gone to the plate 548 times for the Cream City Nine, roughly the equivalent of a full season’s worth of work. In that time he’s produced a .282/.347/.558 slash for a 133 wRC+, with 34 home runs, 104 runs batted in, and 79 runs scored. Fangraphs pegs his value at 3.4 wins above replacement as a Brewer. Aguilar appears to have taken his game to another level this season by improving his plate discipline and approach against fastballs, and a strong argument can be made that right now, he’s a top-5 first baseman in all of baseball and deserves strong All-Star consideration. In a couple of days he’ll turn 28 years old, and the Brewers still have another four seasons of contractual control over him following the conclusion of the 2018 championship season. It’s probably still too early to say for certain, and there can be so much year-to-year variance among players, but at this point the conversation is worth giving some thought to:

Should Jesus Aguilar be considered a core piece for the Milwaukee Brewers going forward?

Statistics courtesy of Fangraphs and Brooks Baseball