Closer Encounters: The Importance of a Good Bullpen

One of the statistics I like to monitor as the MLB trade deadline approaches is team bullpen ERA. Over the past three full seasons (2019, 2021 and 2022), I've noticed a correlation between playoff teams and their league ranking in this particular statistic.

Out of the 12 playoff teams from 2022, 11 had a bullpen ERA ranking in the top-half of the league during the regular season:

In 2021, all 10 playoff teams were in the top-half of the league for this stat, while eight of 10 fit the bill in 2019.

Every once in a while, a team overcomes their poor bullpen and still makes the playoffs, like the 2022 Phillies (4.24 bullpen ERA, ranked 23rd) and 2019 Nationals (5.68 ERA, ranked 29th). Both teams advanced to the World Series, with the Nationals winning the title with Sean Doolittle, Daniel Hudson and Fernando Rodney at the back-end of their pen.

Obviously, there are countless factors that impact a team's chances of making the playoffs, but managing an excellent bullpen is at or near the top of the list.

Let's take a look at current bullpen ERA rankings through late June:

Looking at current playoff teams (through 6/27/23 games) in the American League, only the Rangers (23rd) have a bullpen ERA in the bottom-half of the league, while the Yankees (1st), Angels (5th), Twins (6th), Orioles (10th) and Rays (14th) have been fairly reliable in relief.

Conversely, the current playoff teams in the National League have middling units based on team bullpen ERA. Only Atlanta has a top-10 ranked bullpen by this statistic, while the Giants (11th), Reds (15th), Marlins (16th) , D'Backs (19th) and Dodgers (26th) trail behind.

Other playoff contenders, like the Guardians (2nd), Mariners (4th), Astros (9th), Red Sox (12th), Blue Jays (13th), Brewers (17th) and Phillies (20th) could certainly alter the standings over the next few months. It will be interesting to see whether this correlation holds for 2023 playoff teams.

No matter how the playoff picture shakes out, it's quite clear that nearly half of the league will be looking to bolster its bullpen by the August 1st trade deadline.

Based on current bullpen ERA, the Dodgers and Rangers figure to be two of the most active suitors for relief help, but don't discount the likelihood of top-ranked clubs adding to their arm barns as well.

Among last year's playoff teams, only the Guardians (5th-ranked 2022 bullpen ERA at 3.05) and Mariners (6th, 3.33) stood pat with with their respective bullpens during their 2022 playoff pushes. The other 10 playoff teams from 2022 acquired one or more relief pitchers between the All-Star break and the trade deadline:

Astros (1st-ranked 2022 bullpen ERA, 2.80) - acquired Will Smith

Dodgers (2nd, 2.87) - acquired Chris Martin

Yankees (3rd, 2.97) - acquired Scott Effross and Lou Trivino

Braves (4th, 3.03) - acquired Raisel Iglesias

Rays (7th, 3.36) - acquired Garrett Cleavinger

Mets (10th, 3.55) - acquired Mychal Givens

Cardinals (11th, 3.61) - acquired Chris Stratton

Blue Jays (13th, 3.77) - acquired Anthony Bass and Zach Pop

Padres (14th, 3.81) - acquired Josh Hader

Phillies (23rd, 4.24) - acquired David Robertson

Don't forget about the Twins, who traded for Jorge Lopez and Michael Fulmer only to fall short of the playoffs, and the Brewers, who missed a NL Wild Card berth by one game after replacing Josh Hader with Taylor Rogers, Matt Bush and Trevor Rosenthal.

The 2023 Relief Market

The 2023 relief market figures to be red hot in the coming weeks. Looking at the list of 2024 free-agent relievers, we can bucket these pitchers into three categories:

1. Relievers who are likely to be traded
2. Relievers who could be dealt if their teams become sellers
3. Relievers who are unlikely to be traded

Could the White Sox trade their entire bullpen? Given all that Liam Hendriks has gone through this year, I wonder if Chicago will even consider moving him. His current elbow injury and his remaining salary may impact whether or not he's moved, and to where.

Aroldis Chapman, Brad Hand and Brent Suter are three southpaws who will be in high demand strictly due to the fact that they throw left-handed.

Despite their current 4th place standing in the NL West division, the Padres' odds of making the playoffs is still 29.3 percent, making a Josh Hader trade unlikely at the moment. However, if San Diego does choose to sell at the trade deadline, Hader would immediately jump to the top of playoff teams' target lists.

Craig Kimbrel would not be far behind if the Phillies fall out of playoff contention. Kimbrel has been outstanding — yes, I italicized to emphasize just how good he has been over the last month and change. Kimbrel has permitted just one earned run in the month of June with a 0.67 WHIP and 20:3 K:BB ratio over 12 innings.

Jordan Hicks is an interesting name should the Cardinals choose to sell. St. Louis has been has been giving Hicks save chances of late, and you have to wonder if that was intentional in order to build up his trade value.

Maybe the Dodgers' relief acquisition is simply getting Daniel Hudson (knee) back from the IL? Hudson has thrown 8.1 scoreless innings on his minor league rehab assignment thus far with a 13:1 K:BB ratio. Los Angeles is greatly anticipating his return, which is expected this weekend on June 30.

I will likely loop back around to this article with some trade predictions in the coming weeks. In the meantime, which relief pitchers do you think will be on the move this summer?