The save became an official MLB statistic in 1969. It’s a flawed stat, and it doesn't provide much useful information about how well a reliever pitched. That being said, Jim Johnson accumulated 51 saves last year, and only 10 relievers have ever reached, or exceeded, the 50-save mark. Johnson is the first pitcher to break the 50 saves barrier since Francisco Rodriguez set the MLB record of 62 saves in 2008 with the Angels.
My question is this: How did those nine other pitchers (Eric Gagne and Mariano Rivera accomplished this feat twice) perform the season after (and beyond) posting 50-plus saves? Let’s take a look, in chronological order.
Bobby Thigpen, 1990 – 57 saves
Short term: Thigpen posted a 1.83 ERA in 1990 in 88.2 innings. He had a low BABIP (.230) and also kept the ball in the ballpark (0.51). Both of those numbers were well below his career averages. The next season, he allowed twice as many home runs despite pitching in 19 fewer innings, and his ERA rose to 3.49. In 1990, he had an fWAR of 1.8; in 1991, his fWAR was -1.3.
Long term: He was never again as effective as he was in that 1990 season. In 1994, his last professional season, he pitched in 7.2 innings with the Mariners, with an ERA of 9.39. He ended his big league career with an fWAR of just 2.2. Thigpen is a good example to use when mentioning how fickle relievers can be.
Dennis Eckersley, 1992 – 51 saves
Short term: Eckersley had a 1.91 ERA in his 51-save season; he also won the Cy Young award and the MVP award that season. He struck out 10.46 batters per nine innings and walked just 1.24, while keeping the ball in the ballpark (0.56 HR/9). The next season, despite raising his strikeout rate to 10.75, he walked slightly more batters and gave up more home runs. He also had some BABIP issues (.345), which led to a 4.16 ERA.
Long term: He outperformed his ERA that season and the next couple after, but he was never quite as good as that 1992 season (understandably). Considering he was 37 years old when he amassed those 51 saves, though, it's still impressive that he pitched six more seasons and was still relatively effective.
Randy Myers, 1993 – 53 saves
Short term: After a 3.11 ERA season in 1993 in which he pitched 75.1 innings and posted an fWAR of 1.7, Myers pitched in just 40.1 innings the following season with a 3.79 ERA.
Long term: He had another mediocre season with the Cubs in 1995 before being rejuvenated in Baltimore after signing as a free agent. In 1996, he struck out a career best 11.35 batters per nine innings, though he did have a BB/9 of 4.45. Still, he managed a 3.53 ERA and picked up 31 saves despite a .351 BABIP. He was even better the season after, saving 45 games and finishing with an ERA of 1.51 (thanks to an insane 0.30 HR/9 and his BABIP also dropping 71 points from the unlucky season before). Myers finished fourth in both Cy Young and MVP voting that season. He didn't pitch in the majors beyond 1998.
Rod Beck, 1998 – 51 saves
Short term: Even with all of those saves, Beck posted an fWAR of just 1.1 in 1998. He followed that 51-save, 3.02 ERA season with a 5.93 ERA in about half as many innings pitched in 1999.
Long term: Beck was again effective in 2000, when he had a 3.10 ERA with the Red Sox in a 1.0 fWAR season. But he had Tommy John surgery following the 2001 season, causing him to miss the entire 2002 season, and he was out of the majors a couple years later.
Trevor Hoffman, 1998 – 53 saves
Short term: Hoffman’s best season was in 1998, when he had a 1.48 ERA and an fWAR of 3.0. He also finished second in Cy Young award voting. The next season, he wasn't quite as good, but still had a 2.14 ERA in just six fewer innings.
Long term: For the most part, Hoffman performed very well after 1998. He had a couple seasons that were aided by extremely low BABIPs -- in fact, his career BABIP was only .263 -- but he was able to keep both his walks down and the ball in the ballpark. He only finished with an ERA above 4 one time -- in 2010 (5.89), which also happened to be his final MLB season.
Mariano Rivera, 2001 – 50 saves; 2004 – 53 saves
Short/long term: Rivera is one of the best and most consistent relievers of all time, so I'm simply including both of his 50-plus-save seasons here. Not counting his rookie season, he's finished every year with an fWAR of at least 1.3 -- except for last season, when he tore his ACL in a freak pregame incident in Kansas City. Regardless, I wouldn't be surprised if he returned to his dominating self in his farewell 2013 season.
John Smoltz, 2002 – 55 saves
Short term: Smoltz finished with a 3.25 ERA in that solid 2002 season, but he was even better in 2003. That year, he pitched in 16 fewer innings but was nearly unhittable, posting a 1.12 ERA and this ridiculous combination: 10.21 K/9; 1.12 BB/9. He also surrendered just two home runs in those 64.1 innings.
Long term: The best overall pitcher of everyone included in this list, Smoltz dominated as a starter from 1989-1999, was a shutdown reliever during the four seasons after his Tommy John surgery, and then returned to being a very good starter for a few seasons after leaving the bullpen. Smoltz is 25th all time with an fWAR of 82.5.
Eric Gagne, 2002 – 52 saves; 2003 – 55 saves
Short term: Gagne followed his 52-save season with an insane 55-save year in 2003, when he posted a 1.20 ERA and a ridiculous 4.5 fWAR. He also struck out nearly 15 batters per nine innings in 2003, which is just absurd. In 2004, his ERA dropped to 2.19 but he still accumulated 45 saves.
Long term: After 2004, he was never the same pitcher and was out of the game after 2008. Still, in that three-year stretch, he was worth 10.9 fWAR – an incredibly difficult task for any reliever.
Francisco Rodriguez, 2008 – 62 saves
Short term: Rodriguez burst onto the scene at age 20, and it didn't take him long to develop into a solid closer. He saved an insane 62 games in 69 chances in 2008 despite 1) not pitching as well as his 2.24 ERA indicated, and 2) basically only being used in save situations (68.1 innings pitched). He had a great strikeout rate of 10.14, but he also walked plenty of batters as well (4.48 BB/9). In 2009, he walked a career high 5.03 batters per nine innings and had a 3.71 ERA (and a fortunate .250 BABIP).
Long term: He had a couple of decent seasons in 2010 and 2011, but he wasn't very good in 2012 (4.38 ERA) and is currently a free agent at age 31. While not pitching that effectively, he's also had some off-the-field troubles and could very well be nearing the end of his career.
Picking up a large number of saves (especially more than 50) essentially requires three things: 1) pretty/very good (but not necessarily amazing) pitching, 2) lots of save opportunities, and 3) good health. Johnson, obviously, had all of those things working for him last season. But, as shown above, reaching that 50-save mark is a great achievement, but it doesn't mean he'll be able to maintain any stretch of fantastic pitching. Guys like Rivera, Eckersley, Hoffman, Rodriguez, and Myers are some of the best relievers of all time, and Smoltz (more valuable as a starter) and Gagne (injury issues) were dominant in a handful of seasons. Johnson's goal should be not to end up like Thigpen and Beck -- relievers who had a couple decent seasons but weren't in the majors that much longer after their 50-save years.
So what does all this mean for Jim Johnson? He can still be effective by continuing to get plenty of groundball outs, keeping the ball in the ballpark, and maintaining a low walk rate. It's certainly important for him to stay healthy, but his low strikeout rate is a concern (more on that here) -- he has the lowest strikeout rate of all the 50-plus-save pitchers. It's unlikely that he'll approach 50 saves again -- his career high before last season was 10 -- and more importantly, it'll be difficult for him to keep his ERA below 3. Sure, anything is possible, but I just wouldn't count on his continued dominance for very long.