We’re witnessing two of the best second halves for bullpens in history.

Translated by Jose M. Hernandez Lagunes

Let’s start with this: the concept of “half a season” is fallacious. It is set at the All-Star break, which is always beyond 81 games into the season (77 pre-expansion) in contemporary baseball. In 1973, with the All-Star Game on July 24, teams played, on average, 97.5 games in the first “half” of the season and 64.4 in the second “half.” In 1937, when the All-Star Game was on July 7, there were 66.9 games in the first “half” and 87.9 in the second “half.” So when sites refer to the first and second “half” of a season, they’re not talking about what happens when you divide a number by two.

And, since I’m going to discuss relievers, we have to consider their use. The All-Star Game has divided seasons into halves since 1933. In the second half (I’m going to stop using scare quotes) of the 1946 season, the Tigers relievers, in 80 games played by the team, pitched 64 innings in 42 relief appearances. In the second half of the 2018 season, Rays relievers, in 66 games played by the team, pitched 378 innings in 243 relief appearances. The role of relief pitchers has changed dramatically over time. So I am going to limit this analysis to the Age of Expansion, from 1961 to the present.

Having finished this preamble, let me explain what I am doing. I’m looking at the best bullpens during the second half of the season. I have already defined the middle and explained the seasons to consider. As for “better”, I decided not to use ERA or RA9. There’s that issue of legacy brokers; If a reliever comes in with the bases loaded and no outs and allows a triple and then strikes out three times, his ERA is 0.00. I’m more interested in how relievers do against single hitters.

But that raises another issue: park and season settings. In the second half of 1968, the Dodgers relievers allowed a batting line of just .217/.270/.265…playing at a local park with a racing factor 87 for right-handed hitters (that is, it suppressed scoring by 13%) and 90 for left-handed hitters, in a league that hit .243/.300/.341. In the second half of 1996, Expos relievers allowed a .209/.285/.307 line with a fracing actor in the local park of 101 for righties and 109 for lefties, in a league that hit .262/.330/.408. Clearly, the Expos’ .592 allowed OPS, given the circumstances, is more impressive than the Dodgers’ .535.

Baseball-Reference features a stat, sOPS+, that scales to an average of 100 for a given split. According to the site, “A number greater than 100 indicates the batter (pitcher) did better (worse) than the League in this split… League averages are for the Major Leagues as a whole and include batting by pitchers . sOPS+ is not adjusted to the park”.

For our purposes, the sOPS+ is not perfect. Ideally, it would be park-adjusted, comparing only to AL and NL averages, and excluding pitchers. But in this case, the perfect is not the enemy of the good. I will take the sOPS+ as a superior evaluation tool to ERA, RA9 or OPS to evaluate the relievers of a team. Using sOPS+here are the top 10 bullpens from the second half of the Expansion Era, in full seasons only.

You may remember some of those teams. The best of them, the 2012 Rays, didn’t even make the postseason. Their 90-72 record was only third-best in the AL East and they finished three games behind the two Wild Cards, Baltimore and Texas. The 1966 White Sox finished fourth. But they all had winning records.

And, as you can see, there are two teams from this season on the roster, the Guardians and the Dodgers. (This season’s data is through September 24.) They’ve gotten there in different ways. The once-reliable Dodgers closer, Craig Kimbrel, has allowed a .666 OPS in the second half and has been relieved of his post. But Chris Martin has allowed .340, Alex Vesia .363 y Evan Phillips .370.

Instead, Cleveland’s closer, Emmanuel Class, has been dominant: .177/.213/.226 allowed in the second half. have been joined Sam Hentges (.280 OPS allowed), Nick Sandlin (.480) y James Karinchak (.498) to form a scary bullpen backside.

Overall, the two teams are tied for eighth in the Expansion Era. Given that we’re talking about 1,778 team seasons—all since 1961, except for the shortened 1972, 1981, 1994, 1995 and 2020 seasons—that’s pretty cool, right?

But that is not all. Until 2020, no reliever had to start an inning with a runner on second. Zombie Runner has changed that. So let’s look at the 2022 Dodgers and Guardians bullpens in the second half.

As ridiculously good as the Dodgers are, they’re just 5-8 in extra-inning games, 3-3 since the All-Star break. The Guardians have been better, 12-4 overall, 5-2 in the second half. However, each has fallen victim to zombie runners. Fewer than 3% of second-half games in the Dodgers’ bullpen have cost them 23 OPS points. For the Guardians, less than 4% of their games have added 10 points to their OPS.

Where would the two clubs, of all time, rank if it weren’t for the zombie runners? Taller, obviously. I estimate both would be in the top five or top seven, with sOPS+ in the 59-61 range. Since the All-Star break, we’ve seen two historically outstanding bullpens lead their teams to the postseason. But if it wasn’t for the zombie runner, they’d be even better.