By: Douglas Young
In 2018, Blake Snell put together a historic season. He was the CY Young winner where he posted a 1.89 ERA. Snell did not have the same success in 2019, succumbing to a 4.29 ERA. His FIP, xFIP, and SIERRA stats suggest he was a slightly worse pitcher between 2018 and 2019, however, they do not suggest a 2.40 difference in ERA. When equating the advanced stats to his ERA, they suggest Snell was lucky in 2018 and unlucky in 2019 (See figure 1). Undeniably, luck was a factor, however, it does not tell the whole story as evidenced by his poor pitching with runners in scoring position.
(Figure 1, FanGraphs)
In 2018, Snell was extremely tough to score on. He led the league by 2.7% in LOB% with a LOB% of 88%. The next year, his LOB% of 71.6 was around the league average – far from the MLB’s best. FIP, xFIP nor SIERRA weigh situations where pitchers have runners on base. This explains why Snell’s ERA changed so drastically leaving his advanced stats somewhat constant.
Industry standard does not believe in clutch players, and thinks that LOB% is a measure of luck. Blake Snell is the exception – his LOB% is not a result of luck. The difference in his walk rate between low-medium leverage situations and high leverage situations is statistically significant at the .025 level with a t-score of 2.16. Snell is walking more batters during the games most decisive moments, that compounds his problems. His declining pitching performance looks like a control problem as his HR rate also spikes during high leverage situations with a t-score of 1.55. While it is not statistically significant at the level .025 it should not be discounted completely. He is either missing the zone completely or missing his spots and giving up more homeruns. This is in stark contrast to his 2018 campaign. In 41 TBF in high leverage situations, he only gave up three walks and one homerun. A pitcher’s ability to manage high leverage situations are key for limiting runs. Snell did not manage high leverage situations well in 2019 and almost 20% of the runs he allowed were during these situations.
(Figure 2, FanGraphs)
From looking at just the advanced stats, many would believe Snell’s deteriorated ERA was from misfortune. Bad luck is undeniably true, however, there were additional factors at play that cannot be discounted. Snell’s 2.40 difference in ERA can be explained from his poor performance in high leverage situations, slightly worse performance overall (shown by his advanced stats), and a swing in luck. His poor performance in high leverage situations exemplifies one variable in a larger equation which should not be overlooked.