The biggest bullpen improvements

Which teams have dramatically improved their pen?

Anyone that watched the Royals even a little bit knew they had a bad bullpen in 2023. Their relievers finished the year with the second-worst ERA in baseball with the second-highest walk rate and fourth-highest home run rate. If the Royals have any hope of contending in the near future, they’ll have to improve a bullpen that has had an ERA over five three times in the past six seasons.

A quick turnaround is possible. The 2007 Rays lost 96 games, but a year later they were in the World Series, in part by lowering their bullpen ERA from 5.31 to 4.17. But that wasn’t even the biggest improvement in recent memory. I took a look at the ten biggest bullpen improvements by ERA since 2000 to see if there was anything the Royals could learn.

2022 Orioles - 5.70 to 3.49

The 2021 Orioles had 28 blown saves, most in the American League. The next year they had just 13, fewest in the league, while the team overall improved by 31 games in the standings to win 83 games. The strikeout rate did not improve much, but they were able to throw many more strikes, dropping the walk rate from 10 percent to 7.9 percent, third-best in baseball.

The Orioles improved despite trading their best reliever in 2021 - Cole Sulser - to the Marlins. Failed starter Jorge López became an All-Star reliever with a 1.68 ERA. Félix Bautista was once released by the Marlins due to high walk rates, but joined the Orioles and got in better shape and learned to throw strikes, using his 100 mph fastball to become one of the best relievers in baseball as a 27 year-old rookie. Dillon Tate dropped his walk rate from 8.0 to 5.5 percent. The team claimed lefty Cionel Pérez and righty Bryan Barker off waivers, and both turned in fantastic seasons.

2005 Indians - 4.90 to 2.80

The 2004 Indians weren’t really that bad in the pen, they did fine in strikeouts and walks and got good performances from David Riske, Rafael Betancourt, and Matt Miller. But closer Bob Wickman was hurt, veteran Rick White was awful, and they tied for the league lead with 28 blown saves.

But the 2005 Indians bullpen had the lowest walk rate in baseball and the fewest blown saves. Wickman returned to lead the league with 45 saves despite a low strikeout rate. Bobby Howry was coming off injury, so the Indians signed him to a cheap one-year deal and he responded with a 2.47 ERA and one of the league’s best walk rates. Scott Sauerbeck was another injury reclamation project that missed all of 2004, but came back in 2005 to have a solid season. Veteran Arthur Rhodes was also acquired in a trade and pitched well, although he missed time due to injury. The bullpen improvement helped in the standings - Cleveland went from 80 wins to 93 wins in 2005.

2011 Diamondbacks - 5.74 to 3.71

The Diamondbacks really turned things around in 2011, going from worst (97 losses) to first (94 wins), thanks in part to a huge improvement in the pen. The team tried to improve on the worst save rate in the National League by signing closer J.J. Putz to a two-year, $10 million deal, and he responded with a 2.17 ERA and 45 saves in 49 opportunities. They acquired David Hernandez, a failed starter with the Orioles, as a return for dumping the salary of slugger Mark Reynolds and he turned into a reliever with the best strikeout rate on the staff. Joe Paterson was a shrewd pickup from the Giants in the Rule 5 draft as a lefty specialist, allowing opposing lefties to hit just .205/.292/.282 against him. They also got a good performance from Micah Owings, a former prospect who never panned out and bounced around the league before Arizona brought him back on a minor league deal.

2014 Mariners - 5.09 to 3.35

The 2014 Mariners had six different relievers make at least 50 relief appearances with an ERA under 3.00. They brought back Charlie Furbush and Yoervis Medina, both of whom were good in 2013. Tom Wilhelmsen simply got better luck, posting nearly the same FIP, with slightly improved peripherals, but his ERA went from 4.12 to 2.27. Danny Farquhar also got better luck - he posted a 1.86 FIP in 2013 but a 4.20 ERA, but was able to turn his 2.86 FIP into a 2.66 ERA in 2014. The true improvement came from signing closer Fernando Rodney to a two-year, $14 million deal, and he led the league with 48 saves with a 2.85 ERA. The team also got good performances from 37-year-old free agent Joe Beimel and rookie Dominic Leone.

2004 Cardinals - 4.79 to 3.01

The Cardinals used free agency to improve their bullpen in 2004. They re-signed lefty Steve Kline to a one-year, $1.7 million deal, and while he had a fine ERA in 2003 (with ugly peripherals), he put up a 1.79 ERA in 2004. Julian Tavarez came over on a two-year deal from the Pirates and made 77 appearances with a 2.38 ERA (although he was caught doctoring the ball that year). Ray King was an afterthought in a big trade for Adam Wainwright, but the lefty specialist made 86 appearances with a 2.61 ERA. Even 35-year-old former Brewers starter Cal Eldred found a second career in the Cardinals bullpen. The result was St. Louis improved by 20 games and won an MLB-high 105 games, falling to the Red Sox in the World Series.

2010 Nationals - 5.09 to 3.35

The Nationals were able to rely on three young homegrown relievers - Sean Burnett, Tyler Clippard, and a 2010 rookie named Drew Storen, a former first round pick. Matt Capps been a solid reliever with the Pirates, but he was terrible in 2009 and was a surprising non-tender. The Nats brought him in and he became their closer with 26 saves and a 2.74 ERA, then flipped him to the Twins for catching prospect Wilson Ramos that off-season. Washington also got solid seasons from two veteran former Royals signed to minor league deals - Miguel Batista and Joel Peralta. Unlike most of the teams on this list, the 2010 Nationals were still bad, losing 93 games.

2015 Astros - 4.80 to 3.27

After years of tanking, the Astros were finally ready to spend again in 2015, and used their money to focus on a bad bullpen. They signed Luke Gregerson to a three-year, $18.5 million deal and Pat Neshek to a two-year, $12.5 million deal. Each made over 60 appearances with an ERA in the 3s. Will Harris and Tony Sipp had each been picked up by the Astros after being let go by other organizations, and put up an ERA under 2.00 with Houston in 2015. Rule 5 pick Josh Fields was also solid for the Astros, although his bigger contribution would come a year later when Houston traded him to the Dodgers for a young outfielder named Yordan Alvarez. With an improved pen, the 2015 Astros jumped from 70 to 86 wins, falling to the Royals in the ALDS.

2007 Royals- 5.41 to 3.89

Before he was assembling a dominating bullpen trio known as “HDH” that would win a title, Dayton Moore dramatically improved a terrible Royals bullpen in his first year on the job. He signed veterans Octavio Dotel and David Riske to one-year deals, eventually shipping Dotel to the Braves that summer for pitcher Kyle Davies. He brought over free agent John Bale over from Japan, and the lefty had a solid 4.05 ERA although he battled injuries. But the biggest acquisition was a skinny unknown kid pitching in Mexico named Joakim Soria. The Royals acquired him in the Rule 5 draft and he posted a 2.48 ERA in his first season on the way to becoming an All-Star

The Royals found success moving starters to the pen. Jimmy Gobble went from struggling starter to effective lefty specialist. Zack Greinke returned from leaving the game of baseball due to anxiety, serving as a reliever and starter and posting a 3.54 ERA in 38 relief appearances. The 2007 Royals still lost 93 games, but the bullpen was third-best in the American League at stranding inherited runners, with the eighth-best strikeout rate in baseball and the eighth-lowest walk rate.