What to expect from Mike Moustakas

The Milwaukee Brewers had a desperate need for an offensive upgrade in the middle infield, and yesterday they went about addressing it in an unconventional way by acquiring third baseman Mike Moustakas from the Kansas City Royals. The soon-to-be 30 year old’s presence will allow the club to move Travis Shaw across the diamond to be the primary second baseman, a position that he’s never played as a professional. Shaw has been working out at the keystone for the last month or so, but the David Stearns and the Brewers understand that they are taking a defensive hit in order to add the biggest offensive upgrade available to the lineup:

“We think Mike is one of, if not the best bat currently available. We think his profile fits particularly well in our ballpark and in our lineup.”

Moustakas was selected as the second overall pick when the Royals drafted him out of high school all the way back in 2007. He was part of a hyped class of Royals prospects around and has served as the club’s primary third baseman for the better part of the last eight years since debuting in 2011 at age 22. That includes pennant winning seasons with the Royals in 2014 and 2015 and a World Series ring in 2015. He’s been largely durable throughout his career, too. Outside of a torn ACL that limited him to 27 games in 2016, Moose has appeared in at least 136 games in each of his full seasons in the big leagues and is on pace to surpass that mark once again in 2018.

During the early portion of his career, it was Moustakas’ reputation with the glove at the hot corner that kept him in the lineup on a consistent basis. He posted below-average wRC+ marks between 75-90 in each season from 2011-2014, but he also accrued +34.2 Fielding Runs Above Average during those years. It wasn’t until his age-26 campaign in 2015 that Moose finally took a step forward with the bat, when he made his first All-Star team while helping the Royals win the championship.

To that point, Moustakas had been primarily a left-handed pull hitter who failed to consistently tap into his raw power. In 2013-14, more than 49% of the balls he put in play were to his pull side. But in 2015 he made an adjustment to help hit the ball back up the middle and the opposite way more often; he dropped his pull rate to 39.2% that season and it has hovered between 39-43% in the four years since. Moustakas was already a skilled contact hitter (15.5% career strikeout rate), and he broke out that year to the tune of a .284/.348/.470 slash with 22 home runs for a 123 wRC+.

In the four years since the start of 2015, Moustakas has posted a .269/.324/.489 slash line with 87 home runs in 420 games, which comes out to a 115 wRC+. He won’t strike out much as alluded to above, but he’s never walked a lot, either; Moustakas owns only a 6.7% walk rate since his offensive breakout and has posted OBP marks of .301, .314, and .309 the last three seasons. Most of the balls Moustakas has put in play in the big leagues have been fly balls (44.1% fly ball rate) and a great deal of them have left the yard in recent years. From 2015-present, Moustakas has a well above-average ISO of .221. Last year he belted a Royals-record 38 dingers and he had already deposited 20 balls into the seats in 98 games this season.

The metrics had dinged Moose’s glovework at the hot corner in recent years (-7.8 FRAA from 2016-17) but he’s bounced back according to the numbers with a stellar +10.2 FRAA so far in 2018. Despite the career-high in homers last season, Moustakas was not a highly sought-after commodity on the winter free agent market and wound up settling for a one-year, $6.5 deal to return to Kansas City with a mutual option for 2019. In 417 plate appearances before finally bidding adieu to the Paris of the Plains this summer, Moustakas was batting .249/.309/.468 with the aforementioned 20 home runs for a wRC+ of 107. The peripheral numbers could portend to even better production with a move to Miller Park.

Among the 160 qualified big league hitters, Moustakas ranks in the top 15% with a 44.2% rate of hard contact. That’s a career-high for him, and slots in behind only the red-hot Christian Yelich among Brewers this season. And yet, Moose’s .247 batting average on balls in play this season ranks as the 13th-lowest among qualified hitters. As someone who primarily hits fly balls, Moustakas is never going to have a very high BABIP, but his total this year is still 20 points below the .267 mark he’s posted since the start of 2015. When you put the ball in play as often as Moustakas, those fluctuations can make a huge difference in terms of bottom-line production. So some better batted-ball luck alone could help Moose see a boost from his current offensive numbers.

Also playing into Moustakas’ and the Brewers’ favor is the boost that Miller Park is known for giving to left-handed hitters. Kauffman Stadium in Kansas City has long been viewed as a pitcher’s park, and the numbers support that the environment does indeed suppress left-handed power. Miller Park, on the other hand, is one of the most favorable places for a southpaw slugger to hit in all the big leagues. Travis Shaw and Christian Yelich have both enjoyed notable offensive lifts since moving from tough parks for lefties, and although he hits right-handed, Lorenzo Cain is enjoying is having arguably the best offensive season of his career after coming from Kansas City to Milwaukee. It doesn’t seem unreasonable to think that a similar surge from Moose’s bat is possible.

The Brewers, currently 10th in the National League with an average of 4.34 runs per game, have struggled to score consistently all throughout the season. The need to lengthen their lineup and strengthen the level of offensive production they were getting from the middle infield positions were the most acutely obvious shortcomings for the club. David Stearns and company have decided to address these issues bringing in a solid gloveman and potent bat in Mike Moustakas to play the hot corner and recalling Orlando Arcia to provide his typical excellent defense at shortstop, which makes it a bit more palatable to potentially punt on defense at second base by moving Travis Shaw and his 114 wRC+ over from third base.

The numbers say that Moose in his current incarnation should be a significant upgrade to Milwaukee’s starting lineup, and the underlying factors at play could mean that he’ll hit even better than before once he starts playing his games for the Cream City Nine. Slingin’ Stearns is certainly taking a risk with this outside-the-box transaction, but after digging in a little deeper, it’s not too difficult to see the potential for the gamble to pay off in a big way down the stretch during the pennant race and hopefully, deep into October.

Statistics courtesy of Fangraphs and Baseball Prospectus