Pittsburgh Pirates: Another Weird Season for Mitch Keller

Despite positng a sub-3 ERA, Mitch Keller did not pitch as well as it may have appeared during the 2020 season. Once again, it was a weird year for the Pittsburgh Pirates young righty.

In 2019, top pitching prospect Mitch Keller made his MLB debut for the Pittsburgh Pirates. That 2019 season was a weird one for Keller. Despite posting an elite strikeout rate and having strong control, Keller had an ERA over 7 due to having the highest batting average on balls in play in MLB history (for a pitcher with at least 40 innings pitched).

Well, the 2020 seson was another weird one for Keller. This time, however, things were flipped for the pitcher the Pittsburgh Pirates hope will one day be their ace. Despite having advanced stats and peripherals that pointed toward a high ERA, Keller posted a sub-3 ERA in 2020.

At a quick glance, 2020 appeared to be a strong season for Keller. The young righty posted a 2.91 ERA in 21.2 innings pitched across his five starts. This included pitching 6 no-hit innings in his penultimate start of the season, and then following that up with 5 no-hit innings in his final start of the campaign.

However, as you dive deeper, Keller’s numbers get ugly. His FIP rose from 3.19 in 2019 to 6.75 in 2020, while his DRA rose from 4.18 to 7.06. Both of these numbers indicate that Keller did not pitch nearly as well as his ERA would indicate.

Adding to his weird season was, once again. his BAbip. After being snake bitten to the tune of a .475 BAbip in 2019, Keller’s BAbip plummeted to .104 in 2020. League average BAbip is .300, this means a .104 BAbip indicates that a pitcher was the beneficiary of strong defense/good luck and is due for major regression.

Keller’s control also was an issue in 2020. After posting a strong 7.0% walk rate in 2019, this number rose to 20.7% in 2020. This included walking eight batters in just 5 innings in his final start of the season. He also struggled to get ahead in the count, as his first pitch strike rate dropped from 63.4% in 2019 to just 46.0% in 2020.

Another concern for Keller in his short 2020 season was the lack of swings-and-misses. His strikeout rate plummeted to just 18.4%, a more than 8% drop from 2019. His whiff rate was in just the 15th percentile in baseball, and opposing batters swung at just 40.5% of the pitches he threw which was an 11% drop off from 2019.

Keller’s pitches were also… weird in 2020. While his fastball velocity dropped nearly 2 MPH from 2019, the pitched remained in the 60th percentile in baseball in fastball spin rate. His slider velocity was also down, but, unlike the fastball, it’s spin rate also dropped as it fell by nearl 2000 RPM. His curveball, however, also had good spin rate ranking in the 63rd percentile in baseball.

Another issue for Keller in 2020 is that he allowed too much quality contact. Opposing batters owned an average exit velocity of 88.5 MPH against Keller, which was higher than the league average. His 42.3% hard hit rate and 11.5% barrel rate were both higher than league average as well. His hard hit rate was 8% higher than league average, while the barrel rate was 5%.

Now, a lot of Keller’s issues in 2020 could be taken with a grain of salt. After all, it was an extremely small sample size of five starts and he also missed time due to an injury. While his control issues could potentially be chalked up to this, that does not make his drop in velocity and swings-and-misses any less concerning.

2021 will be an important season for Keller. Both he and the Pittsburgh Pirates will be looking for him to put it all together next season. Most of all, both parties may just be hoping for a normal season in 2021.