How Quickly Do 'Speed Guys' Truly Decline After 30 Years Old?

Jason CataniaMLB Lead WriterMarch 25, 2013

This past winter turned out rather well in the end for Michael Bourn, but before the offseason free agent found a new team (albeit not as quickly as expected) and a big contract (albeit not as hefty as hoped) there was a lot of talk about whether the veteran outfielder might have trouble living up to whatever deal he signed.

Much of the discussion centered around the fact that Bourn, a speedy leadoff hitter who'd led the National League in steals three straight years before finishing a close second in 2012, was turning 30 over the winter and if that meant his carrying tool—his speed—would soon decline.

Bourn had entered the offseason as arguably the top center fielder available on the market and with hopes of a big-money deal in the $75 million to $100 million range over five or six years. He wound up signing well after most other free agents in mid-February with the Cleveland Indians for four years and $48 million guaranteed.

It's hard to call $48 million "disappointing," and certainly there were other factors at play that pushed Bourn's price tag down, but the concern over how valuable a player who so relies on his legs would be as he entered his 30s was both obvious and intriguing.

After all, in baseball they say speed, unlike hitting, never slumps.

But does speed decline with age? And if so, how much? Where is the cutoff point? And what does this mean for "speed guys" like Bourn?

First, let's define and quantify a "speed guy." Stolen bases are as good a place as any to start, so let's set the standard at 30 steals in a season. It's not infallible, but for the most part, a 30-steal season is a pretty good benchmark for determining if a player could be labeled a "speed guy."

Over the past 20 seasons (1993 to 2012), then, there have been a total of 351 individual 30-steal seasons, about 17 or 18 on average per year. Of those 351...

...a whopping 240 were compiled by players who were 29 or younger at the time—or 68 percent.

...just 111 were accomplished by players 30 years old and up—or 32 percent.

Here's a chart:

That's pretty strong evidence that speed begins deteriorating once a player reaches the big three-oh, but then that's also simple logic—and biology. Age and speed are constantly fighting an inverse battle: As age increases, the body's ability to expand and contract muscles—like those needed to run—begins to slow, and speed decreases. Naturally.

But! We can try to fight off nature, at least a little bit, by honing in on a tighter age bracket as a way to prevent comparing, say, a 23-year-old stallion of a ballplayer to a 38-year-old has-been with a pair of bad knees.

In other words, it would be unfair to pit Jake Taylor against Willie Mays Hayes in a race, so let's even the playing field some.

To that end, let's see just how damning the age-30 barrier is by focusing on the specific range from 27 to 32 years old. Since those six years typically encompass a player's "prime," it stands to reason that we might expect less variance—and a less drastic drop-off—right? In theory, a 31-year-old isn't all that different in physical ability and performance compared to a 28-year-old.

Using the same time frame (1993 to 2012), there were 180 total 30-steal seasons from players in their prime. Incidentally, that's almost exactly half of the 351 cited above. Of those 180...

...a whopping 109 came from players who were in the first three years of their prime (ages 27 to 29)—or 61 percent.

...just 71 were achieved by players in the last three years of their prime (ages 30 to 32)—or 39 percent.

Again, a chart:

So there is less variance within the prime years, but the disparity is still pretty stark and the evidence is undeniable: Once a player reaches age 30, there is a noticeable decline in speed, as measured by 30-steal seasons.

Now that we've established that, let's go a little deeper by examining how speed dwindles over the course of the 30s.

Sticking with our familiar time frame of 1993-2012, here are the number of 30-steal seasons at each of the following specific ages...

Age 30: 24

Age 31: 29

Age 32: 18

Age 33: 7

Age 34: 8

Age 35: 8

Or for the more visual learners:

And you get the idea. Bottom line: Once a player passes through his final peak season at age 32, the chances of a 30-steal campaign are remote.

Again, this isn't a perfect measure, but it's a pretty good one. And it buoys the notion mentioned at the outset of this piece—teams were not incorrect to worry about how Bourn, now 30, would hold up as he reached the tail end of his prime, which just so happens to coincide with the end of his contract, as he's signed through age 33 (with a vesting option for his age-34 season).

As for what this means going forward, well, it's provides us with a good idea of how some other "speed guys" might fare when they reach their upcoming free agency.

While last March we saw Cameron Maybin ink a five-year, $25 million contract, and just two weeks ago fellow speedy center fielder Carlos Gomez earned himself a three-year, $24 million deal, both of those were extensions given to players still under team control.

Maybin will be 29 and Gomez 30 in the final years of those extensions. In other words, the Padres and Brewers will be getting out while the gettin' is good.

As for the open market, lest we forget, the last two major free-agent contracts handed out to speed guys were the $142 million the Red Sox paid for outfielder Carl Crawford after the 2010 season and the $106 million the Marlins gave to shortstop Jose Reyes.

Funny, but aren't those two no longer with the teams that signed them?

If you're wondering who could be next winter's Bourn, look no further than Jacoby Ellsbury of the Red Sox, who hits free agency with a profile that is similar to Bourn's in many ways: a center fielder with multiple seasons leading his league in steals who also happens to be turning 30 as this season comes to an end.

If what happened to Bourn is any indication, though, teams have learned that no matter how fast you run, age always catches up.