The Old and the Restlesss: Weighted Team Ages
The Astros have a very young team; the Yankees do not. I’m not exactly breaking news here, but I am going to provide you some data to back up the claims. Thanks to the depth charts that we maintain here on the site, we are able to calculate team age not just by the average age of the players on the roster, but weighted by the amount of expected playing time that each player is projected to get this year. After all, having a 25 year old starter and a 35 year old reserve is not the same thing as having a pair of 30 year olds splitting the duty. Young teams often populate their bench and bullpen with veteran leaders, and there’s no reason to dramatically inflate their average team age based on the presence of those backups.
The depth charts also include expected future playing time for guys in the high minors who haven’t yet gotten the call to the big leagues, but should be expected to see some big league time this summer. The Astros weighted team age includes the playing time we’re expecting top prospects George Springer, Jonathan Singleton, and Mark Appel to get in Houston later this year, so this process evaluates a team’s age not just by what they currently have on the team but also the talent that should arrive in the near future.
Without further ado, the data.
The Astros and Marlins have the two youngest teams in baseball, to no one’s surprise. The Yankees, Phillies, and Red Sox are old, but again, this is not new information. But there are still some fascinating pieces of information in that graph.
For instance, the defending NL champion Cardinals come out as the fifth youngest team in baseball. The Pirates 2013 surge — led by core stars such as Andrew McCutchen and Starling Marte — makes them appear as the new young challengers in the NL Central, but the Cardinals are actually younger than the Pirates are, as St. Louis’ seemingly never-ending waves of talent just keep filling holes and providing value at the big league level. There’s a reason everyone wants to copy The Cardinal Way; they win with rosters that are comparable in age to clubs in the midst of long-term rebuilding projects.
Likewise, the Braves also deserve recognition for contending with the third youngest roster in MLB. They spent the off-season locking up the majority of their young core, but this graph is a reminder of just how young the Braves really are. The Cardinals and Braves are the best current examples of teams having both a strong present and future base of talent.
On the other end of the spectrum, I don’t really think of the Blue Jays as a particularly old team, but they rely heavily on R.A. Dickey and Mark Buehrle to carry their rotation, and Jose Bautista is a sneaky older player, since he developed late and doesn’t feel like he’s been around forever. While Bautista is still very productive, he’s also 33, and Edwin Encarnacion is 31. It’s not just the Toronto pitchers that are probably on the downside of their careers, and this is a roster that needs to win in the near future before some reckoning occurs.
Also in the sneaky old category, look at where the Royals and Rays are. Both teams are often talked about as being full of good young talent, but the Royals rotation is Yordano Ventura and four guys on the wrong side of 30, while the Rays lean heavily on 33 year old Ben Zobrist and 31 year old Yunel Escobar. Both organizations have produced a number of franchise-type young players over the last few years, but not as much as of late, leaving them to fill holes with veteran stop-gaps from outside the organization. There’s nothing wrong with having David DeJesus or Norichika Aoki around, but guys like that aren’t going to be productive for that much longer.
The Rays and Royals are two good examples of the trade-offs that contending teams make, however. Generally, older teams win more than younger teams, and if you’re in win-now mode, you have to fill out your roster with some veterans who can still contribute but don’t have much long term upside. The youngest teams are usually not contenders, and can afford to give playing time to guys who wouldn’t otherwise play on a team concerned with maximizing present wins. However, the correlation between team age and expected rest-of-season winning percentage isn’t actually that dramatic.
That’s an r of .34 and a r squared of .12, which means that you can chalk up about 12 percent of the difference in a team’s expected performance to their weighted team age. It matters, but it’s certainly not the driving force that cliches like “experience wins championships” have driven home for years. Older teams are better, but there’s a ton of noise in there too, and just loading up on veterans is no sure way to guarantee victory.
If you’re looking for an ideal combination of youth and current performance, you’re looking at a cluster of teams in that lower right hand quadrant: the Nationals, Cardinals, Rangers, and A’s. On the depressing side of things, there’s the upper left area, which houses the Twins and, most notably, the Phillies. No team in baseball has a worse combination of expected 2014 performance (.470 win%) and weighted team age (30.9 years). The Yankees are the oldest team in baseball, but at least they’re expected to have a winning season; the Phillies are the franchise with both a questionable present and a bleak future.
For those interested in seeing the full weighted age breakdowns by team, for both batters and pitchers, the full table is below.
| Team | Age | BatAge | PitchAge |
|---|---|---|---|
| Astros | 26.9 | 25.8 | 27.9 |
| Marlins | 27.0 | 28.7 | 25.3 |
| Braves | 27.6 | 27.9 | 27.3 |
| Mariners | 27.6 | 27.5 | 27.7 |
| White Sox | 28.1 | 28.5 | 27.7 |
| Cardinals | 28.1 | 29.1 | 27.1 |
| Cubs | 28.2 | 27.4 | 29.0 |
| Orioles | 28.3 | 28.4 | 28.2 |
| Rockies | 28.3 | 28.2 | 28.5 |
| Nationals | 28.5 | 28.6 | 28.4 |
| Pirates | 28.6 | 28.0 | 29.1 |
| Reds | 28.6 | 29.5 | 27.7 |
| Athletics | 28.6 | 29.7 | 27.5 |
| Rangers | 28.7 | 29.1 | 28.2 |
| Mets | 28.8 | 28.5 | 29.0 |
| Indians | 28.9 | 30.1 | 27.8 |
| Padres | 28.9 | 29.0 | 28.8 |
| Royals | 29.1 | 28.2 | 30.0 |
| Rays | 29.2 | 29.8 | 28.5 |
| Brewers | 29.2 | 28.9 | 29.4 |
| Twins | 29.3 | 28.6 | 30.0 |
| Angels | 29.3 | 30.4 | 28.2 |
| Diamondbacks | 29.4 | 29.0 | 29.7 |
| Tigers | 29.6 | 30.7 | 28.6 |
| Dodgers | 29.8 | 30.2 | 29.3 |
| Blue Jays | 30.0 | 29.2 | 30.8 |
| Giants | 30.2 | 29.6 | 30.8 |
| Red Sox | 30.8 | 30.5 | 31.1 |
| Phillies | 30.9 | 30.9 | 31.0 |
| Yankees | 31.5 | 33.0 | 30.0 |
| ——- | ——- | ——- | ——- |
| Average | 28.9 | 29.1 | 28.8 |
| Median | 28.8 | 29.0 | 28.6 |
Dave is the Managing Editor of FanGraphs.


Only #2?
Sigh. More work to do.
“Mr. Jeter, in honor fantastic career and supreme contribution to the game of baseball, the Philadelphia Phillies are proud to offer you…
a major-league guaranteed contract for 2015-2017!”
Jamie Moyer has not officially retired I think – there is hope
I hope Jamie Moyer returns. I want to see Jamie Moyer retire until his arm literally falls off. I want to see Jamie Moyer die, then resurrect as an all powerful lich so he can keep playing baseball.
If you want to see Moyer die, just listen to him on the Phillies broadcast.
Indeed, it would be awesome for the guy who pitched in the majors’ first night game to pitch a game decided by instant replay.
The Phillies can’t even win “Oldest Team in Baseball”
The win “Oldest Team In Baseball Not Called The Yankees”
Hey Moyer! Amaro’s on line 2!
I’m already talking to Amaro on line 1!
I am asking my driver to take my horseless carriage right to the Philly club’s office and ask Senor Amaro for a million dollars per year to be the starting pitcher on all games east of the Mississippi.
(Still can’t believe how much they pay you candy-asses to pitch every fifth day.)
Would it be informative to look at age weighted by projected WAR?
I could be wrong, but I think the point is to demonstrate how WAR peaks at a certain age and declines as players get older. Or, you know, typical anti-Phillies Fangraphs.
Is fangraphs anti phillies, or is RAJ just anti everything that seems to be common knowledge about player age?
Hey, RAJ is no dummy; he sees that upward slope of the best-fit line on the “age versus winning” graph, and carries it to its extreme: if age begets winning, even loosely, then a team full of 55-year-olds should project to win at an .800 clip! Wonder what Omar Daal is doing.
“That’s an r of .34 and a r squared of .12, which means that you can chalk up about 12 percent of the difference in a team’s expected performance to their weighted team age.”
Well no, it doesn’t (emphatically!). We need to be maybe a little less mechanical about reading R2’s; there are lots of possibilities here: omitted variable bias being the obvious one.
Right. It would be as incorrect as asserting that, since winning percentage is positively correlated with salary, that a team should load up on high salaries in order to win. Trade for A-Rod and Ryan Howard, and transform your losing team into a winning team!
I don’t understand. Dave isn’t asserting that teams should look to be older. He’s just pointing out a correlation. We should all understand by now that correlation is not causation.
There is a correlation between age and success (a statistically insignificant one). The causal relationship is probably more along the lines of – players who reach their 30’s in the majors tend to be particularly good at baseball. You want to hire guys who are particularly good at baseball, not old guys. It just happens that the two features have a mild correlation.
what if this was weighted by WAR? Seems like that would be even better than just playing time..although Murray Chase wouldn’t like that.
How would that work for a team like the Astros? Their young players all basically average to replacement level, but they have some vets (Fowler, Feldman) who are kind of good.
Mets are skewed by Bartolo. Also throw in Farnsworth and Valverde, both of which could very easily not be on the team in 2 months. Would be curious to see this without the outliers (2 youngest and oldest players removed from each team).
For once, I thought I’d escape an article with the word “weight” in its title.
Can I weigh in on this?
The gravitational field for the whole Tri-State area is skewed by Bartolo.
“For instance, the defending NL champion Cardinals come out as the fifth youngest team in baseball.”
According to the chart the Cardinals are the sixth youngest, not fifth.
28.1 = 28.1 = Tied for 5th
To be fair, it should have said tied for 5th.
Rounding off to 1 decimal, they are tied. If the chart is accurate, the bars don’t have a rounding limitation and the White Sox are slightly younger.
It is a tale
Told by an idiot, full of sound and fury
Signifying nothing.
Any historical basis for this?
It seems a bit confounded, as the projected wins already account for age.
“the projected wins already account for age”
Huh?
projections for individual players take age into account, team projections are built off individual player projections
You should adjust the Jays’ figures given that soft tossing wonders Dickey and Buehrle are obviously immune to the ravages of age.
Interesting to see the rays as on the older side, especially since they don’t exactly have a bunch of surefire future regulars in their system.
Friedman’s skin must be crawling. He must be itching to dump price for three prospects.
Correct me if I’m wrong here, but there is no indication that this is meant to say which teams will win. On the contrary, I thought he did a good job saying that age doesn’t necessarily imply winning as many (non-fangraphs) people seem to think.
To me, it seemed that this article is merely pointing out weighted ages of teams, and it seems pretty accurate for the 2014 season. My Red Sox are trotting out ancient catchers and aged outfielders along-side an “experienced” (euphamism for old) pithching staff. None of this is meant to suggest that next year will be the same, it’s just a snapshot of average age based on playing time.
A fun activity would be to see the difference between this list and 2002 (for example). Perhaps an indication of the supposed increase in longevity caused by PEDs.
I’m curious what the correlation would be when comparing age to winning percentage 1, 2 and 3 years later.
I’m probably missing something fundamental, but after all the articles over the last few years about how players peak as zygotes, how does one explain that older-than-average teams (29+ years old) tend to win more?
The main reason is that if you are an older player, and still getting significant playing time it is solely because of your results on the field. This means that the older than average players that are still getting regular playing time are much more likely to be strong players in their own right, because there is very little reason to pay huge money for an older player who is replacement level when they can get a rookie in for far less money at replacement level.
To put it more simply there are a few reasons.
1) Older players are more expensive, and have proven results. Therefore they are much more reliable as far as both projections and results on field.
2) Older players might not be as strong as their younger selves, but they are more likely to be the cream of the younger crop so to speak.
3) I am not sure there is as strong of a correlation between age and winning as you seem to think. 6 of the youngest 11 teams have very real playoff chances this season. When you consider that many of those younger teams are essentially intentionally tanking and focusing on their prospects that points a pretty clear picture towards young excellence in my mind.