Depending on the chosen method of understanding performance declines by age, MLB hitters generally start to decline sometime between the time they turn 28 and 30. Nevertheless, some players can have their best seasons after what is typically a hitter’s peak years.
Since many of these hitters have had underwhelming careers before their breakout seasons, they tend to be either late-round picks or left on waivers after drafts. If fantasy owners can recognize these breakout candidates early in the season, then the hitters can be valuable fantasy assets acquired at little to no cost and can become crucial to a team’s success.
For this article, a breakout season is one in which the hitter has his most valuable fantasy season by a significant margin and is worth rostering in most leagues. Whether it be through more regular playing time, improved per-game production, or a combination of the two, the hitters listed below have an unusually high chance of breaking out this season given their age and should be closely monitored by fantasy owners.
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JaCoby Jones (OF, DET) - 28 years old
Jones has struggled at the plate since entering the league in 2016, owning a career .645 OPS. Jones overhauled his swing last season though, and the results were encouraging:
Average Exit Velocity | Barrel % | O-Swing % | Swinging Strike % | xwOBAcon | K % | |
2018 | 88 | 5.9 | 37.4 | 14.6 | 0.392 | 30.4 |
2019 | 91.3 | 10.7 | 32.7 | 11.3 | 0.414 | 28.2 |
Although he’s seen a marked improvement in his strikeout rate, Jones’ high 28.2% strikeout rate still held him back last season. That being said, of the 30 qualified batters to post swinging-strike rates between 11% and 12% last year, none posted a strikeout rate above 27%, and the group average sat at 22%. Jones’ strikeout rate is likely unusually high largely due to his low 66% z-swing rate, so an increased z-swing rate may be a key to his 2020 breakout.
Jones has effectively become a high-strikeout but powerful hitter with a likely to decline strikeout rate in 2020. If he can maintain his improvements from last season while attacking pitches in the strike zone more frequently, then an OPS above .800 with a strikeout rate around 25% is a reasonable expectation.
Given that Jones faces little competition for playing time in a relatively weak Tigers outfield, he should be able to start most games barring injuries. Based on his upside and lack of playing time concerns, Jones should be a late-round flier pick in deeper leagues and someone worth watching as a potential early-season waiver pickup in shallower leagues.
Brad Miller, (2B/3B/OF, STL) - 30 years old
Miller broke out to some extent last season with a .894 OPS over 79 games, but more regular playing time in 2020 thanks to the universal DH and sustained success should make 2020 his “true” breakout year. Miller’s contact quality has quietly been very strong in each of the past two seasons, as he’s posted barrel rates north of 10% and an xwOBA on contact above .430 both years.
In 2018, Miller was hampered by a 32.5% strikeout rate, a number that he got down to a more reasonable 26.5% in 2019. Encouragingly, Miller’s strikeout improvements were built on a lower chase rate (5% difference between 2018 and 2019), an increased contact rate (3.5% difference), and a decreased swinging-strike rate (12.8% difference), suggesting that his improvements should be sustainable.
In addition to Miller’s strikeout improvements, his average exit velocity (91.6 mph in 2019), barrel rate (12.8%), and average launch angle (16.8 degrees) all rose last season. Miller undoubtedly benefited from some luck last season based on his 23.6% HR/FB ratio, but if he can maintain a strikeout rate of around 25% and cut down on pop-ups, then an OPS above .850 is well within reach in 2020.
Yadiel Hernandez (OF, WAS) - 32 years old
The Nationals signed Hernandez in 2016 after the outfielder put up an impressive .324/.449/.487 slash line over six seasons in Cuba, and he’s continued to hit well in the minor leagues with a .301/.385/.503 slash line over three minor league seasons. Hernandez’s mastery of the strike zone (he’s walked 616 times compared to 637 strikeouts over his career) is his primary strength, but it seems as though the Nationals have worked with Hernandez to add power at the expense of strikeouts.
Pre-Nationals Swing:
Nationals Swing:
It’s clear from the leg kick alone that Hernandez has tweaked his approach with the Nationals, and the numbers suggest that he’s sacrificed swinging-strikes for power. In Triple-A last season, Hernandez posted a relatively poor 1.68 K:BB but clubbed a career-best 33 home runs with a career-high 6.5% home run rate. Even in the home run happy PCL, Hernandez’s 6.5% mark was well above the league-average 4% home run rate. It’s also encouraging that Hernandez can punch a home run into the opposite field gap, suggesting that he has at worst slightly below-average major league power.
Overall, Hernandez offers strong plate discipline with roughly average game power and hits to all fields. That gives Hernandez the upside to post an OPS above .750 with an OBP above .340, but his performance will depend heavily on how significant his power gains have been, how often he keeps the ball on the ground, and if he can adjust to major league pitching.
The universal DH should give Hernandez a dark horse opportunity for enough playing time to truly break out in 2020. Fantasy owners (particularly those who value OBP) should monitor Hernandez’s performance this year as a result, and roster him if he claims regular playing time.
Yandy Diaz (3B, TB) - 28 years old
I’ve already written about Diaz here, here, and here, so I’ll keep this short. Essentially, Diaz offers above-average power, plate discipline, and contact skills that should allow him to post an OPS above .850 in 2020. Diaz managed to post a .816 OPS in 79 games in 2019, and he should be able to at least match that performance over a full season this year.
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