The 2020 MLB season was only 60 games, and that small sample size means that some players who had down years may have just been unlucky. There are certain statistics that can help us identify pitchers who were unlucky in 2020. Left On-Base Percentage (LOB%) is the percentage of pitcher’s own base runners that they strand. Expected Earned Run Average (xERA) is the Expected Weighted On-Base Average (xwOBA) converted to the ERA scale. This statistic can tell us how well a pitcher is performing compared to his ERA. FIP, xFIP, and SIERA are other helpful stats for measuring a pitcher’s performance and predicting ERA. Thus, by finding players who have a low LOB% or an xERA that is significantly lower than their ERA, we can see who was underperforming due to bad luck in the 2020 season. Some of those pitchers may be destined for more success in 2021.
James Paxton – SP, Seattle Mariners
Paxton had his worst year by far in 2020 posting a 6.64 ERA over 5 starts. It’s tough to consider 20.1 innings pitched as a season, yet Paxton is being criminally undervalued heading into 2021. Every statistic for Paxton in 2020 suggests he was unlucky before his season got cut short due to injury. He had a LOB% of 55.1% which was worse than any qualified pitcher’s percentage was in 2020. The number is also far lower than his career 73% which is slightly above the typical MLB LOB% average which ranges between 70% and 72%.
In addition, the southpaw has an xERA of 4.24 which was an insane 2.40 points lower than his ERA in 2020. Based on his quality of contact allowed, strikeout, and walk rates, Paxton should have experienced far more success. His FIP of 4.37, xFIP of 4.47, 3.88 SIERA, and crazy high .365 BABIP also make it clear that Paxton was very unlucky in 2020 and should bounceback in 2021. I expect Paxton’s ERA in 2021 to be between his career ERA of 3.58 and 2020 xERA of 4.24 which would be a major improvement from his 2020 performance.
Matthew Boyd – SP, Detroit Tigers
Boyd was horrendous in his 60.1 innings pitched in 2020 as demonstrated by his 6.71 ERA. His FIP, which is a better predictor of ERA than ERA, was 5.78 in 2020 which is a significant decrease. Boyd’s xFIP, an even better predictor, was 4.97, and SIERA, which is even better at estimating ERA, was 4.60 in 2020. The best predictor of ERA, xERA, was 5.31 for Boyd in 2020, which is 1.40 points lower than his ERA. Boyd should pitch to an ERA between his xERA of 5.31 in 2020 and career ERA of 5.08. Another reason to believe Boyd will improve in 2021 is his LOB% of 65.8% in 2020. That number is below his career average of 70.4% and should improve in 2021. Boyd isn’t a great MLB pitcher, but he is better than his 2020 performance entails and he should find more success in 2021.
Luke Weaver – SP, Arizona Diamondbacks
After a promising showing in 2019 demonstrated by his 2.94 ERA, 3.07 FIP, and 4.93 K/BB ratio, Weaver had a down year in 2020. Weaver posted a 6.58 ERA and 3.06 K/BB ratio across 52 innings in 2020. Diving deeper into his 2020 numbers, provides reason to be hopeful about Weaver’s 2021 performance. For starters, Weaver had a low 63.2% LOB% in 2020 which is far below his career average of 69.4%. His 4.67 FIP, 5.06 xFIP, 4.52 SIERA, and 4.67 xERA showcase Weaver’s poor luck in 2020. Weaver’s xERA was 1.91 points lower than his 2020 ERA. The similarities in the ERA predictors provide us confidence that Weaver will have a much improved 2021. The former 1st round pick should have his ERA drop in 2021 to around his career ERA of 4.71 which is right on par with his FIP and xERA in 2020 of 4.67.
Carlos Martinez – SP, St. Louis Cardinals
Martinez had a laughable 9.90 ERA in 2020, but I wouldn’t be too concerned about Martinez in 2021 as he only pitched 20 innings. The two-time all-star had been one of the best pitchers in the MLB from 2015-2019 with an ERA ranging between 3.01-3.64, a LOB% 73.4% or higher, and a strikeout percentage of at least 21.5%. Even in so few innings in 2020, we have many data points that suggest Martinez wasn’t as bad as ERA suggests. His 5.97 xERA was an astronomical 3.93 points lower than his ERA.
In addition, his 5.20 SIERA and 5.21 xFIP give us reason to believe Martinez had bad luck in 2020. As if that wasn’t enough to convince that you that Martinez’s 2020 was a fluke, he also had a ridiculously low LOB% of 47.6%, which will undoubtedly improve in 2021 significantly and be closer to his above-average career LOB% of 75.0%. Martinez may not be as good in 2021 as his career 3.51 ERA, but he should perform way closer to that level than his 9.90 ERA in 2020.
Mike Minor – SP, Kansas City Royals
Minor struggled in 2020 with a 5.56 ERA and 62.9 LOB% after being an all-star in 2019. The southpaw pitched better than his ERA and LOB% suggest he did in 2020. Minor should see his LOB% rise closer to his career 74.1 LOB% in 2021. Minor’s 2020 FIP of 4.64, xFIP of 4.50, SIERA of 4.20, xERA of 4.33 suggest that Minor was unlucky. His xERA was 1.23 points lower than his ERA in 2020; therefore, the former 1st round pick’s quality of contact-induced, strikeout, and walk rates imply that Minor should’ve had far greater success in 2020. The four ERA predictors are between 4.20 and 4.64 providing confidence that Minor will improve in 2021. I expect Minor to have an ERA below 4.64 and closer to his career ERA of 3.98 in 2021. Minor will have more success in the 2021 season in his first year with the Royals.
Yusei Kikuchi – SP, Seattle Mariners
The former Nippon Professional Baseball star went 73-46 with a 2.77 ERA in 1010.2 innings pitched across 8 seasons. The MLB has been less kind to Kikuchi as he has had far less success since joining the Mariners. Kikuchi has accumulated a 5.39 ERA in 208.2 innings pitched in his two seasons with the Mariners. However, his 3.37 xERA, 3.30 FIP, 3.78 xFIP, and 4.34 SIERA suggest that Kikuchi will have more success in 2021. Kikuchi’s xERA was 1.80 points lower than his ERA of 5.17 in 2020 demonstrating his bad luck last season.
He had a 59.9 LOB% in 2020 which would have been the 2nd lowest total among qualifying pitchers. That number is destined to increase and should be similar to his 70.8 LOB% in 2019. That increase will correlate with an improved 2021 season. Kikuchi’s xERA and other ERA predictors insinuate that he should have been one of the better pitchers in the league in 2020. Kikuchi will have a much improved 2021 season and establish himself as an above-average pitcher in the MLB.
Trevor Rogers – SP, Miami Marlins
The 13th overall pick in 2017 didn’t have the best MLB debut in 2020 accumulating a 6.11 ERA across 28 innings. There are many reasons to be excited about Rogers going into the 2021 season. First, he registered a 12.54 K/9 in 2020 which would have ranked 4th among qualified pitchers. The only 3 pitchers with better rates were Tyler Glasnow, Shane Bieber, and Jacob DeGrom. That’s impressive company to be in. Second, all of Rogers’ ERA predictors indicate that he should have had more success in 2020. He had a 4.33 FIP, 3.67 xFIP, 3.86 SIERA, and a 3.53 xERA.
The rookie’s xERA was 2.58 points less than his ERA in 2020. A 3.51 ERA would have ranked 31st in the MLB last year, so Rogers has the potential to be among the solid starting pitchers in 2021. Third, Rogers’ 67.5 LOB% in 2020 was below average and likely to rise as his luck improves. He had a .380 BABIP in 2020 which was higher than any BABIP experienced by a qualified pitcher. Rogers’ luck will absolutely get better in 2021 as his BABIP will decrease. Rogers will make a big leap forward in 2021 as his performance resembles how he should have performed in 2020.
Sean Manaea – SP, Oakland Athletics
Manaea struggled in 2020 as demonstrated by his 4.50 ERA and 60.5 LOB%. I expect a much better 2021 season from the Athletics pitcher. Manaea holds a career 3.85 ERA and career 72.7 LOB%. He should pitch much closer to those marks in 2021 than his 2020 numbers. Manaea had a 3.71 FIP, 3.77 xFIP, 4.01 SIERA, and 3.93 xERA in 2020. These stats imply that Manaea should have had more success in 2020 and provide confidence that he will perform better in 2021. His 2020 xERA was .57 points lower than his 2020 ERA and on par with his career ERA. I expect Manaea to pitch to an ERA below 4.01 and around his career ERA of 3.85 and 2020 xERA of 3.93. Thus, Manaea will bounceback and have a much-improved 2021 season.
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