Identifying the Top Five Bullpens in Baseball Over the Last 30 Days

The state of relief pitching has changed immensely over the past few years and this season is no different. In fact, unlike starting pitching, it is much more difficult to try and predict how a team's bullpen is going to perform over the course of a 162-game season or try to put a finger on exactly who the biggest contributor in a contending team's bullpen will be when the season concludes.

Regardless of that fact and regardless of the idea of identifying individual relievers that are excelling throughout the league, having a successful bullpen that can sustain success over a long period of time is extremely difficult and certainly requires a team effort. After all, baseball is a team sport and no one ever said that only one reliever was going to make a team go from loser to winner in a short period of time. Most of the time, for a team to have a successful bullpen, the team must have 6 or 7 effective relievers that can pitch in different roles when various situations pop-up during a game.

With that being said, let's try to identify who the Top 5 Bullpens in the game over the past 30 days based on various metrics. Granted, this list could completely change between now and the conclusion of the regular season because of the volatility of relief pitching, but it's fascinating to look at nonetheless.

1. St. Louis Cardinals - At the very top of the list are the St. Louis Cardinals who have quietly put together a very effective bullpen. After some struggles at the start of the season, former Cleveland Indians reliever, Andrew Miller, has really been able to put everything together and turn into that effective middle inning reliever that the Cardinals expected him to be when they signed him to a two-year, $25 million dollar contact with an option for the 2021 regular season this past offseason. In fact, over the last 28 days, Miller has held opponents to a (.154) batting average and a (.118) BABIP (Batting Average on Balls In Play). Despite Andrew Miller being successful, he hasn't necessarily been the key cog that has really turned the state of the St. Louis Cardinals bullpen around. That honor belongs to 28-year old, right-hander Giovanny Gallegos. So far during Gallegos first full season at the big league level, he has posted a 2.07 ERA over 61.0 IP with (80) strikeouts and an ERA+ value of (208). Moving forward into the month of September, the Cardinals bullpen is going to play a critical role in deciding if the team is ultimately able to take home the National League Central crown or not. As of late, the Cardinals have pitched at a much higher level and it will be fascinating to see how that success plays out over the remainder of the regular season.

2. Boston Red Sox - When the regular season first started, there was certainly plenty of attention surrounding the struggles of the Boston Red Sox bullpen and rightfully so. From the start of the regular season through April 30th, the Red Sox posted a 4.47 ERA over 110.2 innings pitched with a (4.23) walks-per-9 rate and a (4.60) FIP (Fielding Independent Percentage). However, over the last 30 days the Red Sox bullpen has been very effective and has seemed to find its groove. Over that span, Red Sox relievers have combined for a 2.91 ERA over 108.1 innings of work with a (10.47) strikeouts-per-9 rate and have held opponents to a (.191) batting average. Among the group that has logged innings in the Red Sox bullpen this season, the most effective reliever has been right-hander, Brandon Workman. Workman has split time in the closer role with righties, Ryan Brasier and Matt Barnes, but has garnered a majority of the saves with (8) saves over (13) save opportunities. Another valuable piece of the Red Sox bullpen thus far has been righty, Josh Taylor. Over 38.1 innings logged, Taylor has recorded (50) strikeouts and currently has a 0.00 ERA over his last 7 games. At the July 31st Trade Deadline, the Red Sox ultimately ended up standing pat and not adding a single reliever, which might be based off of how the bullpen group has performed especially over the last 30 days.

3. Houston Astros - Coming in right behind the Boston Red Sox in the American League in terms of best bullpen are the Houston Astros. Houston has worked really hard over the past couple of seasons to build up it's bullpen as illustrated by the trades for both Ryan Pressly and Roberto Osuna prior to last year's July 31st Trade Deadline and the addition of Joe Biagini at this year's Trade Deadline. Over the span of the last 30 days, Astros relievers have combined for a (17.0%) walk-to-strikeout percentage along with the majors highest left on-base percentage at (86.9%). One of the nice luxuries about the Houston Astros bullpen heading into this season was the idea that the team could have a few hybrid pitchers that could start or pitch in relief with guys such as Brad Peacock and Josh James. However, that plan has been a bit derailed throughout the season due to unforeseen injuries which can pop up at any given time for any given team and has caused for a bit of a hit to the overall pitching depth for the Astros. Although, both the aforementioned Roberto Osuna and Ryan Pressly have been highly effective for Houston. Heading into play today, Osuna had (30) saves on the season, while Pressly led the team with (27) holds. Another highly effective arm for the Astros has been right-hander, Will Harris. Harris most effective pitch has been his cutter which has averaged a (2,525) average spin rate and (91.2 MPH) average speed this season.

4. Los Angeles Dodgers - One of the most elite teams this season has been the Los Angeles Dodgers and it's a big reason why the Dodgers had a (19.5) game lead in the National League West at the start of play today. Over the past 30 days, Dodgers relievers have combined for a 3.45 ERA over 88.2 innings of work with a (3.82) FIP and a (24.4%) strikeout percentage. Prior to the July 31st Trade Deadline, there was plenty of buzz amidst the entire Dodgers fan base, as well as the rest of baseball, about the Dodgers trading for a high leverage back of the bullpen arm such as Felipe Vazquez of the Pittsburgh Pirates. While the Dodgers did have discussions regarding Vazquez with the Pirates, the ultimate holdup was the Pirates demanding up-and-coming middle infielder, Gavin Lux, who the Dodgers absolutely refused to give up and based on the team's recent bullpen success, it looks like that might have been a wise decision in the end. One of the best stories to come out of the Dodgers bullpen this season has been the turn around of right-hander, Joe Kelly. Kelly inked a three-year, $25 million dollar deal this past offseason which includes a team option for 2022 and at the beginning of this season it looked like the deal could be a big disappointment, but Kelly has really turned things around since. Since the conclusion of the All-Star Break, Kelly has a 1.98 ERA over 13.2 innings of work with a (.184) Opponent Batting Average Against and (19) strikeouts.

5. Tampa Bay Rays - At the start of this season, it looked as though the Tampa Bay Rays could be a juggernaut with their bullpen and the overall success of the entire 25-man roster. However, once June rolled around, the Rays lost a bit of steam and their pitching staff started to struggle more often than not compared to the first two months of the season. Despite that fact, the Rays continue to rely heavily on their well-engineered plan of utilizing The Opener and will continue to rely on that plan moving forward over the last month of the regular season leading to the postseason. Currently, the Rays are deploying a three-man starting rotation with a ten-man bullpen which is fascinating because it helps to support the point that the Rays like to utilize their pitchers in different roles and use matchups to their advantage as much as possible. Over the last 30 days, Rays relievers have combined for a 3.63 ERA over 124 innings pitched with a (22.8%) strikeout-to-walk percentage and have held opponents to the second lowest Hard Hit Rate over that span at (32.2%). Amid those names that have pitched out of relief this season, one of the most effective has been Emilio Pagan. Pagan has been a very valuable weapon against both lefties and righties all season long and has done well in situations with runners in scoring position where he has held opponents to a .233/.261/.395 batting line over 43 at bats. Over the next month, the Rays are going to call-up plenty of arms once rosters expand in hopes of it bolstering the chance of the team clinching one of the Wild Card spots and if that happens, matchups are going to be the dominating headline.