Breakout Candidates for 2021 – Outfielders

Last week, we took a look at one potential breakout player at each infield position for 2021. Part two of the breakout players series takes a look at three outfielders with the best chances to break out in 2021. As a reminder, the methodology used to select these candidates primarily uses metrics such as xwOBA (expected weighted on-base average), wOBA, hard-hit rate, and barrel rate, as well as some traditional stats, to better identify players that may take the next step in 2021. All stats, unless otherwise noted, are pulled from the player’s Baseball Savant page.

Kole Calhoun

xwOBA: .364

wOBA: .357

Hard hit %: 38.2%

While all of the infield breakout candidates were young players that just haven’t put it all together yet, the 33-year-old Calhoun doesn’t fit the same mold. Still, there’s a lot there to believe Calhoun experienced the beginnings of a late-career surge in 2020.

2020 was the first season Calhoun had spent outside of Los Angeles, having played there since 2012. In his first year with the Diamondbacks, Calhoun slashed a healthy .226/.338/.526 with a 125 wRC+ in 54 games, his best wRC+ since a 58 game sample in 2013. Even more intriguing, there are signs that Calhoun was better in 2020.

Calhoun posted a .264 Expected Batting Average (xBA) and .364 Expected Weighted On Base Average (xwOBA) that outperformed his actual numbers, as well as posting the best barrel rate of his career at 11.8%. That continued a trend he had previously experienced, increasing his barrel rate in each of the past two seasons before 2020. Additionally, he upped his walk rate to a career-high 12.3% while trimming his strikeout rate to 21.9%. His xwOBAcon continued to be well above average at .413, something he’s done for three straight years.

Simply put, Calhoun has continuously posted good underlying numbers and improved in 2020 while upping his surface statistics. It seems the change of scenery from Los Angeles to Arizona has suited him well, and he could make certainly the step from above-average to elite if he continues on that trajectory in 2021.

Byron Buxton

xwOBA: .320

wOBA: .339

Hard hit %: 47.9%

Buxton is one of those players with all the talent in the world but hasn’t quite put it all together yet. A lot of that has to do with health, as he’s played 92 games or less in five of his six seasons in the Majors. Still, he’s begun to turn a corner offensively over the past two years, and further showed signs of a looming breakout in 2020.

After four years of subpar performance to go along with the injury history, Buxton cut his strikeout rate and increased his walk rate in 2019, while also increasing the quality of his contact. He took steps back in plate discipline in 2020, though still kept his strikeout rate well below his pre-2019 levels.

The contact quality was where Buxton made big strides in 2020 that has him on the verge of a breakout. His 13.5% barrel rate, 91.2 MPH average exit velocity, 47.9% hard-hit rate, and .429 xwOBAcon are all borderline elite, and well above his previous bests. Additionally, while his xBA, Expected Slugging Percentage (xSLG), and xwOBA all slightly lagged his actual numbers, they remained close enough to show that the success he had in 2020 was legitimate.

There are some concerns with the plate discipline. He walked at just a 1.5% rate and struck out too much, so he will likely need to improve there to become a true star. He also needs to be cautious with his launch angle, as his 23.6 degree average launch angle is approaching a point where he may be getting under the ball too much. If Buxton can stay healthy, look for him to make those improvements in 2021 and become a true offensive force.

Austin Slater

xwOBA: .401

wOBA: .389

Hard hit %: 45.3%

Slater had spent parts of three seasons in the Majors with very little offensive success prior to 2020, but showed signs of turning a corner in 2020. He slashed an impressive .282/.408/.506 with a 151 wRC+ in a small sample size of 104 PA. However, the underlying metrics show that he may have actually been better than suggested in 2020.

Slater posted a .305 xBA, .542 xSLG, .401 xwOBA, and .458 xwOBAcon that all outperformed his actual numbers. That came with the support of a 14.1% barrel rate, 45.3% hard-hit rate, 45.3% sweet spot rate, and 15.4% walk rate. He also dropped his strikeout rate to a career-best 21.2%. While some might speculate these numbers were small sample size anomalies, there’s reason to believe that some level of success is sustainable.

In 2019, Slater recorded 192 plate appearances of near-average performance, with a wRC+ of 99. The underlying metrics were more optimistic, as his 10.1% barrel rate, .442 xSLG, .432 xwOBAcon, and 11.5% walk rate were closer to his 2020 numbers than his previous career numbers. Really, the biggest concern with Slater’s 2019 was a sky-high 30.7% strikeout rate. Given that he was able to trim that strikeout rate while actually improving his other metrics, it’s promising that his success can be sustained in 2021.

The other big stride Slater made in 2020 was improving his average launch angle. It was rather low from 2017-2019, topping at 3.4 degrees in 2019. He raised it to 10.9 degrees in 2020, a mark not far off of the league average. It allowed him to tap into his power a bit more and likely attributed to the rise in xwOBAcon. Of the three candidates on the list, Slater feels like the one most likely to turn a massive value from a fantasy perspective, given his status as a relative unknown within the baseball community. Look for Slater to make a household name of himself in 2021, much like Mike Yastrzemski has done in San Francisco.

Others to watch: Joc Pederson, Gregory Polanco, Nick Senzel