Was 2020 a Death Knell for the 200 Inning Starter?

I have talked about the 200-inning threshold a couple times before. In the middle of the 2019 season, I checked up on the pitchers on pace to surpass that threshold. At the conclusion of 2019, I suggested that Mike Minor‘s 200th strikeout, controversial or otherwise, wasn’t so significant as his 200th inning. Now, while 200 innings pitched is an impressive feat which signifies both strong endurance and performance, it is also an arbitrary threshold. 198 is not significantly different from 200, yet 200 means something. It’s round! Humans, even empirically oriented baseball types, gravitate toward those round numbers. Try telling Minor, who called Ronald Guzmán off a potentially inning-ending foul ball, that 200 strikeouts isn’t in and of itself appealing.

So let’s lean into the arbitrary, yet again, and consider whether 2020 might be the nail in the coffin for 200 inning pitchers. Of course, 200 inning pitchers weren’t exactly trending even before 2020’s truncated season; from 2016 to 2019, no more than 15 pitchers threw 200 innings in any given season. Those totals are down considerably even from the early 2000s, when just over 40 pitchers, on average, threw 200 innings per season from 2000-2009. Thus, without the intervention of a shortened season, pitchers were still increasingly unlikely to throw 200 innings. However, 2020 may serve to expedite that trend. Below are a couple key reasons 200 innings might become exceptionally rarified space going forward.

I: The Wake of 2020

This one is already an obvious talking point as Spring Training gets underway: pitchers who threw stateside last year didn’t throw nearly so many innings as they otherwise would have and therefore will have adjusted innings expectations going into 2021. Lance Lynn threw more innings than anyone in 2020 and his total was still just 84. Only Lynn, German Márquez, Kyle Hendricks, Shane Bieber and Yu Darvish were tracking to reach 200 innings in 2020, should the season have been 162 games. This phenomenon is additionally significant for minor league players, whose seasons were completely scratched in the wake of COVID’s onset. For both MiLB and MLB pitchers, 2021 will necessarily be a season of caution, restraint, and a slow climb back to some form of normalcy.

Interestingly, playoff pitchers might not be considered to have a “hangover effect” so much as benefitting from additional (albeit high leverage) innings in the playoffs. The Dodgers and Rays would benefit most if this logic is sound (a significant “if”) as Clayton Kershaw, Blake Snell, Tyler Glasnow, Walker Buehler, Julio Urías and Charlie Morton (now with the Braves) each supplemented their regular season workload with 20+ playoff innings in 2020.

Teams are adjusting to this reality in a couple ways. In some cases, teams are doubling down on depth. Having depth, particularly rotation depth, will probably be key as any given team’s best pitchers likely will not provide so large a share of total innings as they are accustomed to. The Rays-Red Sox transaction in recent days seems to be an example of a contender, in the Rays, shoring up their pitching depth. Signing viable 5-8 starters for a depth chart will be of heightened importance for 2021 in light of this load management.

Another route teams have taken is leveraging the workload of pitchers in other leagues. The Mariners signing Chris Flexen (KBO in 2020) and the Rangers signing Kohei Arihara (NPL) are examples of this. Following a severely truncated season, signing pitchers who had success in other leagues in addition to having thrown 125+ innings last year is a probably quite appealing.

II: The Adoption of Six Man Rotations

Google “six man rotation” and there are links to articles for more than a couple teams. Ben Clemens of FanGraphs notes that the Tigers and Mariners will likely both utilize a six man rotation in 2021 while other teams are surely weighing their options. Clemens, in his article linked above, does a really good job illustrating that the primary cost of a six man rotation is, well, that sixth man’s performance. In short, a sixth starter isn’t an ace (or even one of a team’s best five, by definition), and pushing your rotation back a day for that sixth starter translates to a couple more runs allowed over the course of a season.

However, for those members of a “traditional” five man rotation, the extra day might be beneficial. Drawing upon “The Book” by Tom Tango, Mitchel Lichtman, and Andrew Dolphin, there is evidence that pitchers benefit some from that extra rest. They put it best:

“There were 4,456 starts where a pitcher had exactly five days of rest. Their wOBA in these starts was .346. On four days of rest, the same pitchers had a wOBA of .350. While this difference seems small, with 110,937 PA, it is statistically significant, at 2.5 standard deviations from the mean. It seems that the more the pitcher rests, the better his performance. The gain isn’t much, but it seems to be there.”

So counteracting forces emerge to deaden the impact of a six man rotation somewhat. This performance boost, however modest, is surely being considered in addition to pitcher health in 2021. Whatever the case may be for individual teams in actuality though, spreading innings more evenly across more pitchers in 2021 will likely be a necessity. Several earnest six man rotation experiments in 2021 might open pandora’s box: should teams generate enough data to more clearly establish the upside of six man rotations in 2021, the impact of 2020’s shortened season will loom even larger in future seasons.

III: Pitching Depth is Relatively Cheaper

As Andy McCollough of The Athletic puts it (subscription required), “The squeeze continues for baseball’s free-agent middle class“. McCoullough’s article title says it all: mid-tiered players aren’t getting what they used to in free agency. From a team perspective, that might give way to cheaper depth, better five starters, and lessen inherent costs associated with a six man rotation. As I wrote following 2019, there is some evidence that fewer multi-year free agent deals are being signed.

As it relates to cheaper, shorter-term deals, Tony Wolfe recently wrote a great piece for FanGraphs covering the Rays rotation construction this winter. Referring first to Rich Hill and Collin McHugh, Wolfe explains that, “Combined with Chris Archer and Michael Wacha, who each signed one-year deals as well, Tampa Bay has now added four veteran free-agent arms at a combined cost of less than $14 million.” The Tampa Bay Rays, seemingly as always, offer a good case study. As Wolfe articulates, they compiled a 60-80% of a viable rotation (depending on how you view McHugh) for exclusively single-year pacts and relatively modest financial commitments. While the premium players continue to get paid, front offices that are shrewd, miserly, or combinations of the two have options for cost effective contributors. For a lot of teams, starting Hill or McHugh every sixth day is more palatable that the six starter options of years past.

IV: The Third Time Through

Without wading into the decision to pull Blake Snell in the World Series, the data is clear regarding pitcher performance the third time through the lineup. Again handing this off to Tango et al.: “The third time through the order shows an expectation of .354, but the actual performance was .362, or an 8-point advantage for the hitter.”

That evidence, in tandem with load management, makes it tough to envision even the best starters regularly getting the opportunity to pitch to lineups for a third time in 2021. Again, these combined forces act to create a stronger precedent for future seasons. If the performance and, more importantly, health of a team’s starting five benefit even modestly from that additional day of rest, the complexion of pitching staffs and the breakdown of innings pitched might change demonstrably going forward.

This is all speculation of course. In the same way Mike Minor wants his 200th strikeout, Lance Lynn surely wants the ball every fifth day. Not all teams have the rotation depth to support a six man rotation, nor the bullpen depth to take a hardline approach to the third time through the order. Still, 250 inning pitchers have largely gone the way of the dodo (the last such season came in 2011) and 225 inning pitchers were rarer in the 2010s (46) than 40-home run seasons (47). 200 innings might just be next.