Expected ERA (xERA) translates xwOBA into the ERA scale. It’s not necessarily predictive, but it helps us compare to the pitcher’s actual ERA. ERA has some flaws and many factors could affect a pitcher’s ERA. xERA can give us a different way to evaluate a pitcher’s performance since it’s a translation of xwOBA and the amount of contact and quality of contact are taken into consideration.
Devin Williams won the NL Rookie of the Year and he throws devastating changeup. Batting average against his changeup was only .032 in 2020 and his ERA was 0.33. His xERA was only 1.49, leading the majors. The Brewers will definitely rely on him much more in the next few seasons.
Caleb Ferguson had a breakout season in 2020. His ERA dropped to 2.89 and it was 4.84 in 2019. Unfortunately, he underwent Tommy John surgery in late September and we will probably see him again in 2022.
Trevor Rosenthal bounced back in 2020. Rosenthal posted a 13.50 ERA in 2019, which was truly frustrating. In this shortened season, Rosenthal posted an ERA of 1.90 and it’s his career best. Back in 2015, Rosenthal posted a 2.10 ERA and his xERA was 2.75.
Victor Gonzalez was the candidate as Caleb Ferguson’s replacement. He didn’t let the Dodgers down. In his rookie season, his ERA was only 1.33. He had a 2.45 ERA in 4 relief appearances in the World Series.
Trevor Bauer, the 2020 NL Cy Young winner, had a tremendous 2.17 xERA. During the regular season, his ERA was only 1.73. He’s still a free agent at this moment.
Look back at the past 5 seasons. Zack Britton is a two-time All-Star and he was selected to the mid-summer classic in 2015 and 2016 when he was in the Baltimore Orioles. His xERA of 1.84 led the majors in 2015 and he had a 1.60 xERA in 2016. In 2015 his ERA was 1.92 and in 2016, his ERA was only 0.54. He threw 67 innings in 2016 and only gave up 4 earned runs. He made 20 relief appearances in 2020 and also had 4 earned runs. Andrew Miller, another two-time All-Star, posted a 2.04 ERA in 2015 and a 1.45 ERA in 2016. At the same time, his xERA was 2.04 in 2015 and 1.63 in 2016. These great numbers definitely showed how outstanding he was and why the Indians acquired him via trade in 2016.
In the chart, we don’t see many starters. However, Clayton Kershaw, future Hall of Famer, tells us how exceptional he is. His xERA was 2.15 in 2015, a season he threw 301 strikeouts and in 2016 his xERA was 2.02 and he posted a 1.69 ERA, the lowest in his career.
Kenley Jansen led in xERA in 2016 and 2017. That truly indicated that he was the best closer in the majors then. His ERA was below 2.00 in 2016 and 2017 each.
In addition, it’s interesting to see Mike Minor. His xERA was 2.35 in 2017 when he was a reliever for the Royals. He and the Royals agreed to a two-year deal in December. Minor will join the young Royals rotation and it will be worth watching whether he can bounce back after a disappointing 2020, which he posted a 5.56 ERA.
We see that the top 5 pitchers in the xERA in 2019 didn’t finish in the top 5 in 2020. Can one of these 5 pitchers in 2020 finish in the top 5 in xERA in 2021?
No comments:
Post a Comment