Glendon Rusch had a fairly unremarkable career by most standards. After struggling with the Royals early on, the left-hander had two solid years as a back-end starter for the Mets in 2000 and 2001. He then had somewhat rocky stints in Milwaukee, Chicago, San Diego, and Colorado, before retiring with a 67-99 record and a 5.04 ERA.
While Rusch’s numbers don’t jump off the page, buried among them is actually one of baseball’s more interesting statistical anomalies. Rusch’s career ERA was 75 points higher than his 4.29 career FIP, which measures only the factors that a pitcher directly controls—strikeouts, walks, and home runs—and is considered a better indicator of future performance than ERA. The lefty finished his career with 6.63 K/9, 2.80 BB/9, and 1.16 HR/9. Among the 1,226 pitchers who threw at least 1,000 innings, the 75-point difference between Rusch’s ERA and his FIP is the third largest in the history of the game.
A large disparity between a pitcher’s ERA and FIP usually means that he experienced poor results on balls in play. That makes sense because FIP controls for such plays and assumes league-average results on them. Indeed, among all pitchers who reached the 1,000-inning plateau, Rusch’s .326 career BABIP is the single highest in baseball history.
Rusch’s odd statistical profile was most striking during his 2003 season with Milwaukee. That year, Rusch had a 3.87 FIP, which his 88 FIP- indicates was 12% better than league average. At the same time, the southpaw posted a dreadful 6.42 ERA, which, as his 150 ERA- demonstrates, was 50% worse than league average. The culprit seems to be a .381 BABIP that represented the highest mark of any pitcher with at least 100 innings in a season since 1930. Rusch finished with a 1-12 record that year.
Rusch’s high BABIP and large ERA-FIP disparity suggest one of two things: Either Rusch was extremely unlucky in that a disproportionate numbers of his balls in play simply didn’t find gloves; or, for whatever reason, he gave up very hard contact on balls in play, while simultaneously controlling the strike zone and limiting home runs. The numbers suggest that both factors were at work.
First, it doesn’t appear that Rusch was the victim of unusually poor defense. If a team’s defense is bad and its players consistently fail to reach balls in play, its pitcher’s BABIP will suffer. That doesn’t appear to be the case with Rusch, however. According to the most advanced metrics available at the time he pitched, Rusch’s teams were generally middle-of-the-road defensively.
Nor was Rusch’s high ERA the result, first and foremost, of poor sequencing. If a pitcher allows baserunners to score at an unusually high rate, it could mean that he simply gave up hits at the wrong time, rather than being generally ineffective. While Rusch’s 68.8% career LOB% is somewhat low, 115 qualified pitchers who pitched at the same time as he did posted lower rates. The next place to look, therefore, would be at the quality of contact he allowed.
It turns out that Rusch did not surrender hard-hit balls at an unusually high rate. From the time these numbers became public in 2002 to the end of his career in 2009, 268 qualified pitchers posted a higher hard hit rate than Rusch’s 25.5% mark. Furthermore, Rusch’s 11.2% HR/FB ranked just 122nd among his qualified contemporaries, meaning that a disproportionate number of his fly balls allowed weren’t leaving the yard.
While Rusch didn’t give up hard-hit balls at a noteworthy rate, perhaps the hard-hit balls he did allow were hit exceptionally hard. Exit velocity statistics would be extremely useful here. Unfortunately, none exist for the years covering Rusch’s career.
We do know, however, that a disproportionate number of his balls in play were line drives. Of the 374 qualified pitchers who pitched from 2002 to 2009, Rusch ranked eighth with a 23.5% line drive rate. A high line drive rate could suggest that hitters were squaring up Rusch’s pitches and hitting the ball with authority in a way that they weren’t against other pitchers. Again, we just don’t know that for sure.
That said, it seems unlikely that the reasons behind Rusch’s high line drive rate—whatever they may be—fully explain his historically high BABIP. Rusch didn’t surrender line drives at a stratospheric rate, and certainly not enough to account for the huge anomalies in his stat sheet.
Without Statcast data to help make sense of Rusch’s career, the lefty’s case will remain somewhat of a mystery. By the fielding-independent metrics, Rusch was a slightly better-than-average pitcher (96 FIP-) in almost 1,500 innings of work. That’s nothing to sneeze at. Looking at traditional run prevention (114 ERA-), on the other hand, he was significantly worse.
As is usually the case, the truth probably lies somewhere in the middle. Given how dramatically his ERA departed from his strong peripherals, however, it’s fair to at least put Rusch in the conversation as one of baseball’s unluckiest pitchers.
Rusch, of course, was only “unlucky” as far as certain aspects of his performance were concerned. For a career that saw him play 13 big league seasons and pitch in a World Series for the Mets, there seem like far better ways than “unlucky” to describe Glendon Rusch’s time in Major League Baseball.