Matt Stairs, who on Wednesday announced his retirement, was the character actor who had a few decent roles in the 1970s and played solid bit parts ever after. He was a Ned Beatty of a player. He had a fine career. Always on the roster for his offense, he delivered above-average results with the bat in nearly every season. That was good for 13.5 career WAR (wins above replacement), including an excellent 4.1 (to go along with 38 homers) in 1999, but more interestingly he did this over 19 seasons. That's the basic anomaly of Stairs's career: He was one of the best ever at being just good enough.
Most players who stick around as long as Stairs owe as much to overall value as they do to longevity. Babe Ruth had a long time to regress to replacement level after putting up Stairs's entire career and change in a single season. Also, there's a strong relationship between player quality and the age of the player's best year: Hall of Famers tend to peak around age 29, while a player of Stairs's caliber could expect to peak around 25-27. He would still have been mediocre with a full season's worth of appearances: It took him 446 plate appearances on average to produce one WAR. Omar Vizquel, who has had a similarly elongated career, accumulates WAR 60 percent more quickly. Stairs may have been an average player, but how far from the norm was his aging pattern?
Thanks to the idea of an aging curve, we can see how well the average player would do if his career lasted a given length. In this case, "average" refers to the player's rate of rise and decline rather than his overall skill. Let's assume a player's career starts in his first positive WAR season and ends after a season of negative WAR. Using a model for position players based on Jeremy Greenhouse's work, here are some minimum expected career WAR totals based on career length.
|Career Length||Career WAR||Best Season WAR|
The player who ages in an "average" way doesn't have to be very good to stick around for a decade or more. That's because most players tend to plateau more than they peak: The best few years of a players' career are usually his most consistent. Adam Dunn is a good example. But this wasn't the case for Stairs: with WARs of .2, .3, .5, and -.5 from ages 40 to 43, he had a replacement player's prime 15 years after the average replacement player has his prime. Perhaps there are many hitters whose declines would stop for a few years at the age of 40, but we rarely get to see them, as they're already too crappy to justify holding a major league job. Stairs was just good enough, and his skill set was just enough of a good fit, that we were treated to four more glorious, anomalous years.
Sure, each player and each type of player ages differently, and our hero is far from being the only position player with a weird aging pattern. Bill Buckner, with 22 seasons and 12.1 WAR, beats Stairs at his own game. But that's like saying Stan Musial is far from being the only Hall of Famer. Many casual sports fans look for only two types of anomalies: incredible skill or incredible suck. But the closer you look, the more varied the ways in which someone can be strange and therefore interesting. So here we are: Matt Stairs, epochally average.
Stairs's longevity is best expressed in numbers, but that doesn't mean its appeal is any different than that of his being pudgy, bearded, or Canadian. I am fond of him because all of those things are unusual for a baseball player. He was the essence of a walk-off balk, made flesh: He mattered in the game, but his weirdness is the only reason anyone cared.