Playoff Bullpens and the 2018 Cardinals

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The first week of the season is always a touchy time to talk about relievers. Dominic Leone can’t close a game, Greg Holland has literally not thrown a strike all year, and Jordan Hicks throw 600 miles an hour with a slider that destroys worlds. Even at the end of the season, our view of individual relievers is going to be hazy at best. Remember how awful Brett Cecil was last year? He was actually quite solid. Rather than try to dive deep on how any pitcher’s year is going to go, I decided to take a look at the broad trends of how bullpens get used in the playoffs. With the Cardinals expecting to compete for a playoff spot, the front office is likely focusing on the same problem as well. To do this, I took regular season usage and rate stats for all playoff teams in the last two years, as well as playoff usage stats.

First, I looked at the regular-season FIP of each pitcher a team used in relief in the playoffs and took a weighted average to compute an expected bullpen FIP in the playoffs. I compared that to the regular-season FIP of the bullpen to work out how much better each team got simply by using their good relievers more. Next, I looked at what percent of a team’s playoff innings those relievers pitched. Finally, I used the percentage of innings and the difference between regular-season and postseason bullpen FIP to figure out how many runs better per game each team got at run prevention by using only their best guys for longer.

First of all, it’s a lot of runs. Teams saved an average of .3 runs a game through better bullpen selection, which comes out to something like 5 wins a season (49 runs). Playoff teams are essentially adding a Jacob deGrom worth of wins just by not playing bad pitchers. The changes were pervasive- literally every team used relievers for a higher percentage of total innings pitched and used better relievers than they had in the regular season. Bullpens improved from 3.69 to 3.00 in the average FIP they deployed, and teams handed relievers 43% of all postseason innings (against 35% in the regular season). In this, at least, the reality of postseason pitching matches my perception- playoff bullpens are nasty and brutish.

Handily enough for my artsy transition, playoff bullpens are also short. The three most-used relievers on a playoff team averaged about 65% of the total relief innings pitched, strongly contributing to the feeling that the 7th, 8th, and 9th innings are a baseball version of Groundhog Day. For comparison, the three most-used relievers on these same teams occupied about 40% of relief innings in the regular season. A quick note on the methodology- when teams used regular-season starters as relievers, I used their regular-season FIP rather than implying some bonus for switching to relief. When teams used short-rest playoff starters as relievers, I ignored them- largely in the name of calculating stats more easily, but also because it’s very hard to predict if the Cardinals would do that given the chance.

This intro, though it’s hard to call it an intro given its length, is a setup for the main question I want to consider today: are the Cardinals well-built for this style of playoff pitching? To look at this, I constructed some plausible splits for the 2018 bullpen’s innings should the Cardinals make the postseason. I gave 20% of the innings to each of Holland, Leone, and Gregerson. I then gave the next tier down (Hicks, Cecil, Lyons) 10%, with Bud Norris and Matt Bowman taking the rest of the innings. I also lowered Hicks’ FIP from the projected 4.2 to 3.5. I did this for two main reasons. First, I like Jordan Hicks and I’m writing this in a section called Fanposts, so I’m inclined to believe he’s better than the projections. Second, that projection is just kind of nonsense. It’s using a tiny amount of data from when he was a high-A starter, so filling in a good FIP seems to me to be just about as predictive given his stuff. I was actually reasonably surprised by the results. The Cardinals fared quite poorly- their depth just doesn’t stack up favorably given the way bullpens work in the playoffs these days. Despite a solid 3.73 FIP in regular season usage, the optimized playoff workload only dropped the Cards to a 3.62 FIP, and that’s assuming Matheny is managing at a playoff-average level. Basically, the bullpen just isn’t built in a style that provides upside in the playoffs.

Now, there’s nothing wrong with that, per se. At the end of the day, it’s not important to improve in the playoffs. All that matters is being great in the playoffs. If your bullpen is just seven Kenley Jansens, improvement is just not a thing you need to worry about. The problem is that the Cardinals don’t have 8 great relievers. They have something like a half of a great reliever, two above-average guys, and a whole pile of better than average guys that work out to a good bullpen. I thought I was partial to this style of bullpen until recently, because it’s just been so temptingly easy to fall out of bed and land on a serviceable reliever. By relying on the John Brebbia/Ryan Sherriff model of serviceable reliever, the Cardinals could spend more of their disposable income on Dexter Fowler, rather than picking up a lower-tier outfielder. In 2014, a trained monkey could run a 3.6 FIP, although Craig Edwards might worry about whether his batted ball luck was sustainable. It just doesn’t feel like that’s the case any more. The bullpen arms that used to be interchangeable are just a little worse in the playoffs, and that adds up to a real, measurable difference.

My first thought upon looking at this data was that it’s a problem with projections versus actual data. Is it really so surprising that all the Cardinals relievers are close to league average, given that projection systems more or less project relievers to be league average? I ran the rest of the NL playoff contenders through a similar test to see.


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The effect is still there, although much smaller. While the Cardinals bullpen is fine overall, it improves meaningfully less than the rest of the playoff contenders. This really matches how I feel watching the Cardinals this year. There is no reliever I dread seeing take the mound aside from Tui, who I’ve mercifully projected for 0 postseason innings, but no one aside from Hicks who I’m excited to see coming in. This isn’t a huge surprise, since the Cardinals seem to have spent the offseason stockpiling adequate but unexciting relievers at every possible turn, but it really drove home for me the sneaky problem with building a bullpen via depth instead of stars.

Okay, so let’s say that we think this is a problem. The bullpen is all 6s and 7s, with nary a 9 in sight. What can the Cards do about it? Luckily, a lot. First, they can go out and acquire an impact reliever midseason. This isn’t really in character for the front office, but given the continued crowdedness of the upper minors, Mozeliak certainly has the prospects to do it without feeling too badly about lost potential. Second, existing Cardinals could just be better. Want to create a great bullpen? Let’s take 2015 Greg Holland (3.27 FIP, even I am not optimistic enough to go for 2013’s 1.36), 2016 Luke Gregerson (2.99), 2017 Dominic Leone (2.94), 2017 Tyler Lyons (2.86), and sub in Trevor Rosenthal’s rookie numbers for Hicks (3.09). None of these are too crazy, and that’s a top-shelf bullpen, even in the playoffs. You can probably even afford one of those guys not to perform, as presumably somebody from the mass of mid-level nobodies and Bud Norris will put up a great season.

So, did we learn anything from comparing the Cards bullpen to the changing landscape of playoff baseball? I have two major takeaways from this research. First, it’s not a mirage- postseason bullpens are nasty, and the one the Cardinals have assembled doesn’t really resemble what we’ve seen in recent Octobers. Second, there’s absolutely no guarantee that the season-ending pen won’t be elite. The raw stuff is there, and the results were even there in the past. It will just be a matter of putting it together- if the season ends with the bullpen looking like it does today, and no one has broken out, the Cardinals will be at a material disadvantage in the late innings of the postseason.