Four years ago, Miles Mikolas pitched for the Texas Rangers. He spent most of the season in the minors and pitched with the big club for only two months. Before the 2014 season, he bounced between the minors and the majors with the San Diego Padres in 2012 and 2013. After the 2013 season, San Diego traded him to the Pittsburgh Pirates, who then traded him again to the Rangers before the start of the 2014 season.
He made his last appearance on August 25th of that year against the Seattle Mariners, lasting eight innings, allowing three hits and one walk while striking out five hitters. It would be his most notable performance, apart from when he ate a lizard during an Arizona Fall League game in 2011, well before his complete game shutout on Monday against the Kansas City Royals.
Mikolas signed with the Yomiuri Giants of Nippon Professional Baseball after the 2014 season. After three seasons of solid pitching in Japan, he returned to MLB and signed with the St. Louis Cardinals, and he has quietly shed his journeyman, replacement level performances and become one of the better starters in the league.
Improving his Performances
Through the first almost two months of the season, Mikolas has had a solid yet somewhat unspectacular output. His 2.24 ERA, 3.29 FIP, and 3.15 xFIP rank seventh, twenty-first, and fourteenth among all qualified starting pitchers. He has significantly improved upon his 6.44 ERA, 4.77 FIP, and 4.51 xFIP in his two-month spell with the Rangers.
Even with the quality performances, anyone would still not mistake him for Max Scherzer. Mikolas has put up a 6.86 K/9, a career high. But while he does not strike out a lot of hitters, he has an astonishingly low 0.90 BB/9. Only the immortal Bartolo Colon has a better BB/9 among qualified starting pitchers. More importantly, his improvements from NPB have worked back in MLB. While in Japan, his K/9 improved each season, jumping from 6.6 in 2015 to 8.2 and 9.0 in 2016 and 2017, respectively. He also recorded a BB/9 above two in NPB only once, and that happened during his shortened 2016 season.
Making Some Adjustments
Even with his improvements, Mikolas has not changed too much after his stint in Japan. Opposing hitters have recorded their highest hard-hit rate, 35.5%, against him this season. He has a ground ball rate (GB%) of 51.7%, which nearly matches his GB% from his time with the Padres. Hitters have only made small and insignificant changes in their swing and contact rate tendencies, and he has not significantly changed the number of pitches he puts in or close to the strike zone.
He has, however, made two notable changes. First, he has changed his pitch mix. Since his return to MLB, he has relied on off-speed pitches, both a curve or a slider, more often than ever. He has thrown off-speed pitches over 45% of the time in 2018. Before his three seasons in Japan, he only once threw his off-speed pitches over 30% of the time (33.28% in 2012). But he has made a far more significant improvement: throwing more first-pitch strikes. Mikolas has the highest first strike rate in the majors among qualified pitchers with a 71.3% first strike rate. Before his three years in NPB, he only managed first pitch strike above 63% in 2013, when he only threw 1.2 innings in the majors. Because he throws first pitch strikes, he has thrown only 19.6% of his pitches while behind in the count, which makes hitters significantly less productive and aggressive.
So, can Miles Mikolas sustain his excellent start? The answer is, possibly. He has a .266 BABIP against, indicating he has received a little bit of luck in his return to the majors. He might not fully sustain his low walk rate or his excellent ERA, but as long he continues to throw first-pitch strikes and keeps hitters off balance with his new and more varied pitch mix, Mikolas will easily maintain his current spot as the number two in the Cardinals rotation.