Mike Moustakas’ Rise to Success

From 2010 to 2011, Mike Moustakas was clearly one of the top ranked prospects in the game. In 2010, the former number two pick overall hit 36 HRs split between Double and Triple A, and was a major part of the Roayls’ elite farm system. Despite only producing an 84 wRc+ over 365 PAs in his major league debut in 2011, his future still looked very bright. However, in the three seasons that followed, from 2012 to 2014, Moustakas failed to break out offensively in the way that many experts had expected. Despite strong defensive metrics that boosted his 2012 fWAR up to an impressive 3.4, he never even approached a league average wRc+ in any of his first three full seasons. Actually, from 2012-’14, his wRc+ declined each year (90, 77, 76 from ’12-’14, respectively). His minor league power seemed to diminish, as he only hit 20, 12, and 15 HRs from ’12-’14, with ISOs of .171, .131, and .146, respectively. Not only was he not improving as a hitter, he was actually getting worse. He had received at least 500 PAs in each season, so injuries clearly were not to blame.

Fortunately for the now back to back American League Champion Royals, Moustakas finally broke out offensively in 2015, hitting .284/.348/.470 (all career highs) in 614 PAs, while also putting up career highs in HRs (22), ISO (.186), wRc+ (124) and fWAR (3.8). Let’s examine the underlying factors that contributed to Moustakas’ breakout year.

One of the most glaring improvements Moustakas has made is in his batting average, considering how low it was the previous three years. In 2015, he hit an impressive .284, which is much better than the .242, .233, and .212 marks he put up from ’12-’14, respectively. One of the most obvious reasons for this increase in batting average was his increase in BABIP, which finally approached league average this past season at .294, which was his best since his abbreviated 2011 season. In the previous three seasons, Moustakas’ BABIPs were .274, .257, and .220, respectively. In fact, his 2014 BABIP of .220 was the lowest in the majors amongst hitters with at least 500 PAs, coming in a full 11 points lower than the next lowest (Brian McCann’s BABIP was .231 in ’14).

Low BABIPs are often times due to bad luck, as the stat will often regress back to the mean, which is roughly .300. However, part of the reason for his low BABIPs has to do with his batted ball profile. Specifically, Moustakas has always hit an extremely high number of infield fly balls, which very rarely, if ever, fall in for hits. Although still hitting a high percentage of infield fly balls in 2015, his IFFB% has decreased since 2012, when 17.6% of the balls he put in play were infield fly balls (which was the fourth highest mark in the majors that year, amongst hitters with at least 500 PAs). It decreased to 16.6% in 2013, and 15.1% and 15.3% in 2014 and ’15, respectively. Although his 15.3% IFFB% in 2015 was still the tenth highest in the majors amongst hitters with at least 500 PAs, it still showed improvement over his early career levels.

Despite the improvement, his still high IFFB% is probably a major reason why Moustakas’ BABIPs have always been so far below average (along with his obvious lack of speed). However, his IFFB% was actually slightly higher in 2015 than it was in 2014, which is odd since his BABIP increased from .220 all the way up to .294 from last year to this one. Actually, his batted ball profiles were strikingly similar in the two aforementioned seasons, leading me back to something I mentioned earlier: the fact that BABIPs are oftentimes due to luck and usually stabilize over time, although a player can have either consistently high or low BABIPs due to factors like batted ball profiles or speed.

Moustakas was seemingly unlucky BABIP- wise in 2014 (and therefore, also with his low batting average, which obviously has a positive correlation with BABIP), and probably somewhat lucky BABIP- wise in 2015, since I wouldn’t expect a player with Moustakas’ lack of speed and very high propensity for infield flay balls to consistently have a BABIP that is around league average. So I’d expect Moustakas’ future BABIP to be somewhere in between the .220 mark from 2014 and the .294 mark from 2015, although probably closer to the ’15 mark, as his BABIP in ’14 truly was exceptionally low. So, based on this (regarding batting average), I wouldn’t expect Moustakas to be a high average hitter like he was this past season (where he hit .284), but he should hit higher than the .212 mark he produced in 2014. On the other hand, a low K% could help counter a low BABIP when it comes to batting average, and as we’ll see, Moustakas’ strikeouts have decreased dramatically.

As mentioned above, Moustakas clearly improved is in his K%, which has declined steadily since 2012. From ’12-’15, he posted K% of 20.2%, 16.1%, 14.8%, and 12.4%, respectively. Having his career best K% in 2015 is another reason why Moustakas increased his batting average up to .284 this past season, as more balls put into play magnified the positive effect his BABIP (which also increased dramatically in 2015) had on his batting average (more balls put in play, rather than strikeouts, means that his BABIP applies to a larger number of his at bats, therefore increasing batting average). Also, 12.4% is very impressive for a K%, especially for a hitter with power like Moustakas demonstrated in 2015. Moustakas’ BB% also increased, from 6.4% and 6.2% in 2012 and 2013, to 7% in both 2014 and 2015. His plate discipline also clearly improved.

Looking further into Moustakas’ plate discipline uncovers more evidence that he’s fundamentally improved as a hitter. His percentage of swings and misses (SwStr%) has steadily decreased since 2012 (he had SwStr% of 10.8%, 8.8%, 7.5%, and 7.1% from ’12-’15, respectively, per Fangraphs), which also correlates with his decreasing K% mentioned in the previous paragraph. His total Swing% has also decreased steadily each year, starting at 49.7% in 2012, and ending at 48% in 2015, per Fangraphs.

This improved plate discipline helps to explain the increase in BB% Moustakas has experienced. His Contact% has also increased each year, up to 85% in 2015 (per Fangraphs), and he has also set career highs (not including his shortened 2011 season) in Z-Contact%, with 91.4% (Z-Contact% = % of balls inside the strike zone a batter makes contact with) and Zone%, with 44.5% (Zone% = % of balls a batter sees that are in the strike zone), per Fangraphs. This shows that not only is Moustakas seeing more balls in the strike zone, he’s also making contact with a higher percentage of them, which helps to explain his decreased K%, as well as partly explain his increased batting average in 2015.

Moustakas’ breakout 2015 success definitely had a lot to do with both his career high BABIP and career low K% (which led to his greatly increased batting average), as well as his career high BB%. The steady improvement over the past four seasons in his K% and BB% show that his plate discipline and contact ability are clearly getting better. However, I would expect his BABIP to decrease somewhat from its 2015 level in 2016 due to his batted ball profile (he very often hits infield flyballs, which almost never fall for hits). However, it’s unlikely that his BABIP will be as low as it was in 2014, when it was the worst in the league amongst hitters with at least 500 PAs. Luckily for Moustakas, he also finally showed some power in 2015, with 22 HRs and a .186 ISO. If he could keep on hitting for power, he should be able to remain very valuable despite an almost inevitable drop in batting average, which seems likely to occur unless his batted ball profile dramatically changes. His ISOs were particularly high in the last two months of 2015 (.209 and .243 in August and September/October, respectively). If he can retain some of that extra, late- season power into 2016, he may even surpass his total 2015 value as a player, even if his batting average decreases somewhat, as should be expected.

Although Moustakas took somewhat longer to emerge as a franchise cornerstone than many experts thought he would back when he was a top prospect in 2011, he is now a key piece of the Royals core. Although he clearly has some flaws as a player, he’s a very solid third baseman who has decreased his K% to the point where it is now very impressive. If he can continue to hit 20+ HRs with an ISO near .200, he should sustain his value in the coming seasons, especially since he just turned 27 this past September.