A year after unexpectedly mounting a World Series run, the New York Mets are experiencing a bit of a pennant hangover in 2016. They started the season hot, with a 15-7 record, but since then have gone 49-56 — basically the same winning percentage as the lowly Phillies’ full-season mark. Even granting that World Series teams usually regress to the mean the following season,1 the Mets have backslid more than most.
Searching for answers, New York manager Terry Collins pointed a finger at his team’s health woes, specifically suggesting that its playoff run last fall contributed to a spate of pitching injuries that have seen most of the Mets’ vaunted staff miss time this year.
“We don’t make excuses here,” Collins said. “But I’ve had too many guys that have managed deep into the postseason tell me that there is a residual effect. And a lot of times, it’s your pitching.”
He’s right that the Mets have been among the most injured teams in baseball. But the link between that fact — particularly on the pitching side — and the extra rigors of New York’s World Series run is questionable. Since the Division Series began in 1995, there’s been no relationship between the length of a team’s stay in the postseason and whether its pitchers met expectations the following season.
To quantify this, I set a team’s pitching expectations — according to the sum of wins above replacement (WAR) for its staff — in a given season based on its pitchers’ WAR in the preceding year, as well as their average age (weighted by WAR) that year. The better the pitchers were one season, the better they’re likely to be the next, and younger staffs tend to improve their WAR year over year. (For example, the 2015 Mets had the sixth-most pitching WAR in baseball, and were also its 12th-youngest staff, so they figured to be very good again in 2016.)
If deep playoff runs were subsequently associated with the mass disintegration of pitching staffs, we would expect a relationship between the number of postseason games a team played one year and the amount by which its staff WAR missed expectations the following season. Yet, no such relationship appears to exist:
The 2016 Mets would be a curious choice as flag-bearers for a World Series pitching hangover anyway. Despite the injuries, they’ve compiled more pitching WAR than any team in the major leagues this season, wildly exceeding any reasonable expectations we might have assigned them before the campaign began. Injured or not, New York’s hurlers aren’t the problem.
However, a lineup that’s scoring an anemic 3.83 runs per game (third-worst in baseball) and producing the majors’ 11th-fewest WAR (in a tie with Colorado) is. If the Mets’ pitchers have exceeded expectations in the team’s pennant defense, their position players have declined precipitously from the form that led to a World Series berth — particularly that of the late-season version that transformed itself offensively after acquiring Yoenis Cespedes at the trade deadline.
So Collins probably shouldn’t get too caught up in speculating about a World Series hangover for his pitchers. Almost every team’s staff has to fight through injuries and underperformance, but deep postseason runs don’t historically tend to amplify those issues. And more importantly, if the Mets’ hitters were providing its league-leading staff with any kind of support, they wouldn’t be on the fringe of the postseason picture right now.