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Pitchers Whose 2020 We Should Ignore

The 2020 season proved to be a struggle for numerous players. Some players dealt with a decline in skills or age-related regression, while others fell victim to the new and bizarre challenges prompted by the COVID-19 pandemic. From the absence of fans to uncertain scheduling, players faced an unprecedented set of circumstances that altered routines and the rhythm of the season. Due to these external factors, it's fair to question how much we can glean from a player’s statistical performance in 2020. Here we will look at a few pitchers whose 2020 numbers we can safely overlook as we project for a less chaotic 2021 season.


Jack Flaherty


Flaherty’s 2020 was marred with inconsistent scheduling and random interruptions. After providing a quality performance opening night against the Pirates, Flaherty wouldn’t make his next start for over a month. An early August COVID-19 breakout within the Cardinals’ clubhouse halted their play for weeks, leaving Flaherty and his fellow pitchers with no facility to properly practice and stay ready.


When their season did recommence, Flaherty was put on a pitch count to protect his health. Flaherty did not reach the 90 pitch plateau until September 10th against the Detroit Tigers, where he gave up two runs in five solid but uneven innings.


Flaherty’s surface stats were underwhelming, putting up a 4.91 ERA and 1.22 WHIP in his 40 and one-third innings. Digging deeper into his performance, there is evidence Flaherty was mostly his normal self. If you take away his disastrous performance in Milwaukee, he had a 3.13 ERA. His xFIP was 3.42 and his SIERA was 3.89. His slider was still elite, he was still averaging 94 MPH on his fastball and he was still getting an ample amount of swing and misses, shown by his career-best 14.3% swstr%. Given the odd shape of his season, I feel comfortable tossing out his 2020 numbers and going back to drafting Flaherty as an ascending top 10 pitcher. Flaherty left no doubt of this when he struck out eight in six superb innings against the Padres in game three of their WC series.


Luke Weaver


After showing glimpses of his ceiling in 2019, fantasy managers were looking forward to an encore in 2020. Instead, Weaver compiled a 6.58 ERA and 1.56 WHIP. I’m buying for 2021, however. Like Flaherty, Weaver’s velocity was consistent with last season (94.1 average MPH in 2020) and his best pitch was still effective. Weaver’s changeup maintained an 18.2% swstr% and a healthy 42.3% o-swing%.


Weaver’s other two pitches, his cutter and curveball, were likely responsible for his struggles. Weaver was leaving his curveball in the zone and not throwing his cutter in the zone, shown by these contour maps. His curveball’s zone% rose from 32.3% to 55.2% from 2019 to 2020 and his cutter’s zone rate fell from 62.6% to 34.2%.



Since he couldn’t throw competitive cutters, hitters were able to attack his fastball more confidently. He particularly struggled against lefties, yielding a .405 wOBA to them. Over the course of the season, he pulled back on the cutter and curveball, becoming mostly a two-pitch pitcher. This put a lot of pressure on his fastball command, and hitters wound up hitting his fastball pretty hard.


These issues appear to be relatively fixable. Weaver was thought to have above-average command as a prospect and rates well on numerous command metrics. It’s not hard to foresee Weaver improving his pitch location and being able to use his cutter again, especially since it has been such an important part of his repertoire for years.


The first part of ignoring Weaver’s 2020 results is the assumption that he will be able to make his cutter and curveball competitive pitches again. The second part is realizing the 6.58 ERA is likely a caricature of his struggles. Despite the ERA, he still posted a 4.67 FIP and 4.52 SIERA, indicating he did struggle but also suffered from poor batted-ball luck. Statcast also tells a similar tale, with his .316 xwOBA and 4.58 xERA being significantly lower than his wOBA (.362) or ERA. These numbers aren’t very good, but compared to the bottom-line numbers it is clear poor luck contributed to his outlier ERA.


Weaver’s career has been a roller coaster, featuring glimpses of brilliance, stretches of poor performance as well as injuries. 2020 was another bump in the road, but Weaver still possesses four solid pitches, above-average velocity, a plus changeup, and solid command.