Starters Are Pitching in Relief More Often This Postseason

The narrative of this postseason has been the ubiquity of the reliever, the increased tendency of teams to use their bullpens early and often. To a certain extent, that narrative is grounded in reality. We saw it right away in the American League Wild Card Game, for example, when the Yankees’ Luis Severino recorded only a single out and then a quartet of New York relievers pitched what was essentially an impromptu bullpen game. Combine that with the paltry two innings that Ervin Santana procured for the Twins and just 13.5% of the innings in that game were completed by starting pitchers.

The next night played out similarly, as Jon Gray and Zack Greinke survived just five half-innings between them, or 29.4% of the game’s total.

So, yes, relief pitchers have played a major role in the postseason. The use of bullpens, however, might not represent the greatest break from tradition. To quote a powerful sorcerer, things aren’t always what they seem.

Yesterday, Travis Sawchik (and before him, Jeff Passan) explored the possibility that, more than facilitating a takeover by relievers, what the postseason has done is blur the lines between starting and relief roles. I have been pondering this question myself, so with a little data help from the venerable Jonah Pemstein, I decided to look into it. What we found is that starting pitchers are being used in relief more than ever before.

Anecdotally, of course, we’ve seen this coming. FanGraphs’ postseason database only goes back to 2013, but in the four years prior to this one, we have a substantial list of star starting pitchers who have worked in relief. That list includes Chris Archer, Madison Bumgarner, David Price, Clayton Kershaw, Dallas Keuchel, and Jon Lester, Max Scherzer, Noah Syndergaard, and Adam Wainwright. If you’re a devoted baseball fan/reader of this site, you can probably pull up the memories of Bumgarner and Kershaw pitching in the bullpen quite easily, and perhaps some of the others as well.

This season, Lester, Price, and Scherzer have all come out of the ‘pen again, as have Lance McCullers, Jose Quintana, Robbie Ray, and Justin Verlander among others. Combine the two lists and you essentially have a who’s who of the decade’s best pitchers. Other easily recognizable names like John Lackey, Rick Porcello, Danny Salazar, Alex Wood, and others dot the list. But that’s all anecdotal, right? How does it break down statistically?

Let’s start with this season. We’ll examine it by round.

There are a number of observations to make here. First, it appears as though starting pitchers have thrown more often as the playoffs have gone on. Obviously, it’s a small sample size in each row. There were two WC games and 17 LDS games. So far, there have been just five LCS games. So it’s probably best not to draw any strong conclusions on usage by round. Still, it seems possible that this trend will continue, that starting pitchers will receive more work in relief as the prospect of the World Series has drawn closer. Maybe there’s nothing to that; maybe there is.

That’s the first point. Here’s the second: overall, the percentage of innings that traditional starting pitchers are throwing seems right in line with what one would have expected in this pre-paradigm-shift world. Sixty-four percent of the innings thrown in this postseason have been recorded by starting pitchers, with “starting pitcher” defined as someone who started 50% or more of the regular games in which he appeared while with his current team. Those innings aren’t necessarily coming as starts, but they’re coming nonetheless.

It’s the sort of thing that makes you wonder if the starters would be getting more length otherwise. Take ALDS Game 4, for example. Rick Porcello didn’t exactly have an easy time of things. He allowed three runs in three innings, but he had retired four of his last five hitters when he was pulled. With the Houston lineup about to turn over for the third time, taking him out was certainly defensible, but would Boston actually have taken him out if Chris Sale weren’t ready to launch on Alert Five? Maybe. Maybe Joe Kelly would have been in early, like he was in Game 3. But maybe Porcello would have been allowed back out there. After all, he only failed to work five innings in three of his 33 starts this season.

No matter what we think the reasons for this may or may not be, using starting pitchers in relief roles is trending up. Here’s the breakdown since 2013:

Now, I don’t want to say that we’re heading for “record” territory, because again, there were 108 postseasons before 2013. More, if you count what happened in the 1800s. But in terms of the last five years, we are set to set a new standard. Already, the mark for the past five years has been broken, thanks to Collin McHugh’s appearance last night. Right now, more than one in four relief innings this postseason has been thrown by a starting pitcher. That’s pretty significant, especially considering that there are/were some pretty good bullpens in the postseason this year. (Six of the eight best bullpen units reached the postseason.)

Now, maybe the percentage won’t end up being as high for the entire playoffs: if you look at the first table, you can see that the percentage of relief innings tossed by a starter has trended downward as the playoffs have gone on. The percentage could also be thrown off by the Yankees, who have been the team who has leaned on starters in relief roles the least of the four teams that remain:

It used to qualify as a rare occurrence, a special event, when a starting pitcher came out of the bullpen. When Randy Johnson emerged to help the Mariners win Game 5 of the 1995 ALDS, it was just his second postseason appearance and first as a reliever. It was similarly special when he came out of the bullpen in Game 7 of the 2001 World Series. In between those two events, he made 12 postseason appearances, all starts. Pedro Martinez’s most famous postseason appearances is arguably his relief effort in Game 5 of the ’99 ALDS. He had 15 other postseason appearances, 14 of them starts. The 15th, Game 7 of the 2004 ALCS, was very much maligned. At that point, very few people wanted to question Red Sox manager Terry Francona, given what Boston was on the verge of accomplishing. And yet the wisdom of that decision was still very much called into question. Fast forward to 2017, and it’s a decision that would fit right in.