As a baseball fan, who recently relocated to Toronto, I feel like I should have at least a passable knowledge of what’s going on with the Blue Jays. My interest in baseball developed while living in Texas, and I have been a supporter of the Texas Rangers ever since – you might know that the Rangers and Blue Jays have a bit of a history. As I was browsing the various Statcast leaderboards from last year, I came across Teoscar Hernandez and his progress in 2020.
Statcast formulates the xwOBA metric based mostly on launch angles and exit velocities of a particular hitter’s batted ball events, and uses that data – along with walks and strikeouts – to predict what the hitter’s wOBA “should” be. And based on xwOBA, Hernandez was the third most improved hitter in baseball in 2020. The coach in me wanted to look under the hood and see, first, what drove Hernandez’s progress, and second, how sustainable it was and whether there were any red flags or possibilities for regression.
Starting with the various projections for 2021, Steamer and ZiPS are split regarding Hernandez’s offense:
In 2019 Hernandez’s offensive output was worth 1.8 runs above average, and that number spiked to 12 runs in 2020. While both Steamer and ZiPS see Hernandez as a well below average fielder, ZiPS seems to mostly buy Hernandez’s improvements, projecting him to be worth 9.9 runs above average in 2021. Steamer, on the other hand, is skeptical, and expects Hernandez’s offense to regress to 2019 levels. So how did Hernandez go about increasing his offensive metrics in 2020?
Looking at the table above shows that the driver behind Hernandez’s xwOBA increase was the fact that he simply hit the ball harder: his average launch angle stayed the same at 15.3 degrees, while his exit velocity metrics increased. He squared the ball up more often, going from 11.7% to 18.0% barrels; as a result, his hard hit percentage (the percentage of balls that left his bat at 95mph+) jumped to 53.1%, and his average exit velocity increased by about 2mph.
Breaking down Hernandez’s hitting statistics by pitch type reveals that his increase in both xwOBA and exit velocities was achieved almost exclusively by punishing fastballs.
Hernandez’s xwOBA on fastballs was an astronomical .486, driven by a 20 degree launch angle and an average exit velocity of nearly 97mph. However, there is a problem with putting all your eggs into the fastball basket.
While being an elite fastball hitter, Hernandez has struggled with hitting breaking and offspeed pitches. In the past three years, his xwOBA on breaking balls is yet to surpass .300, and he has been swinging and missing at them at a rate of about 40% or worse. He has been able to improve his whiff percentage on the offspeed stuff, but has been pounding those pitches into the ground with an average launch angle of 7 degrees. The worrying part, for Hernandez anyway, is that pitchers have noticed, and he has been seeing fewer fastballs: from about 57-58% in 2018 and 2019, to about 53% in 2020. The decrease in fastballs has been offset by an increase in the number of offspeed pitches thrown to Hernandez, but given the data above, I would not be surprised if he starts seeing a larger share of breaking balls in 2021.
Moreover, Hernandez so far hasn’t show the ability to get on base consistently in a different way than pounding the fastball.
His 2020 strikeout rate of 30.4% was in the 12th percentile for all batters, while his walk rate of 6.8% was in the 24th percentile. Walks and strikeouts are certainly not the end-all-be-all, but Hernandez is well “above” the MLB average in terms of his whiff percentage – 36.0% for his career as opposed to 24.5% MLB average, caused in large part by his below average zone contact percentage: 71.5% for his career as opposed to 82.8% MLB average.
Baseball is a game of adjustments, and it will be interesting to follow Hernandez’s 2021 season. I would not be surprised if Hernandez saw less than 50% fastballs going forward, and it will be up to him to show the pitchers that he can handle the breaking ball in the zone. Given the league-wide trend of overall decreasing fastball usage – and Hernandez’s limited contributions on defense – learning how to do damage on something other than fastballs is a critical skill for Hernandez’s future as a major league contributor.