In 2012, Fernando Rodney had a season for the ages, saving 48 games with a 0.60 ERA in 74.2, an MLB record for a minimum of 50 innings pitched. But there was no chance whatsoever that he was going to repeat such performance–or even come close. The following is the list of MLB relievers who have managed multiple seasons of 50 or more innings and an ERA of 1.50 or below: Mariano Rivera. Yes, Mariano Rivera and no one else. But even though we knew that Rodney would regress significantly this season, none of us expecting anything like this. After yet another blown save on Wednesday, Rodney’s ERA sits at just 5.40, with 25 strikeouts but 17 walks in 18.1 innings pitched.
Other than Rodney, seven pitchers had relief seasons with an ERA below 1.00 in 50 or more IP. Their average ERA the next season was 2.81, still very good–after all, you have to be an excellent pitcher to have a season like that. When we expand it to bullpen arms who managed a season with an ERA of 1.50 or below in 50 IP, we have 59 pitchers, 54 pitchers of whom played a significant number of games the next season, and a similar result, an average of 3.14. The median value is 2.96 and is more indicative of the average value in this case because Hung-Chih Kuo‘s ERA after his 1.20 ERA season was 9.00 in 27 appearances. Rodney’s 5.40 ERA would be the highest value of any pitcher other than Kuo, with only Shigetoshi Hasegawa and Rafael Betancourt also registering ERAs over 5.00. Only six even had ERAs over 4.00. If the annals of baseball history tell us anything, Rodney can’t possibly be this bad the entire season. And if Rodney keeps struggling to this extent, it wouldn’t be regression to the mean but an utter collapse.