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Age, Winning, and Questioning Assumptions

Does a team's average age have an effect on winning percentage?

Youngster Domonic Brown with Veteran Michael Young
Youngster Domonic Brown with Veteran Michael Young

[Editor's Note: Please welcome Ben Horrow to Beyond the Box Score. Ben comes to us from SummerPastime and That Ball's Outta Here, and will be contributing link reaction pieces several times a week.]

Readers, fans, and other interested parties in baseball unanimously understand and accept that multiple factors contribute to a baseball team's success or failure. We tease apart those aspects one by one, hoping to create a map of contributing factors, that not only further the understanding of the game, but more importantly, advance baseball to the next level.

We don't need a rigorous analysis to be convinced that the quality of skill and talent of the players on a given team make up the largest portion of the pie chart of success. Skill, talent, and ability are broken down into hundreds of maxims and metrics giving all who analyze that piece of the game the thrill of exploration and innovation.

Other elements add to said pie chart, but to a lesser extent. Some of these include a team's coaching staff, medical staff, and ballpark, in addition to more variable measures like weather patterns. In a recent article concerning the future of the Philadelphia Phillies for, Jonah Keri, known best for his book, "The Extra 2%," explored one of these non-talent aspects of a team's overall success.

Put simply, age often implies, and predicts, success.

Let's not get too carried away without some context. Keri spent the first few paragraphs of his piece mentioning that teams with older players can prove successful or disastrous, and the same can be said for predominantly younger teams. Still, he wrote, albeit generally, "age often implies, and predicts, success." I know as a fan, I often lament front offices that employ mainly older rosters, hoping for the right mix of young players and veterans that we all assume leads to prosperity. But, does this notion that an age-balanced team will win more games prove true?

Using data since 2008, I analyzed teams' winning percentages and their average age to uncover a correlation. One simple regression later, I discovered that a team's average age contributes only 12 percent of a team's winning percentage (R^2 of .12038, P < 0.001). For the details check out this Google doc.

Although this analysis completely disregards other effects of a team's age, it gets to the heart of the aphorism "age implies and predicts success." Question these ideas, no matter how intuitive they may seem, just as fellow BtBSer Glenn DuPaul did in this Hardball Times piece on home field advantage and PITCH F/X.

Does age imply and or predict a team's success? In the grand scheme it probably doesn't but, for some reason, our minds tend to think it does. When we see lopsided ages in our favorite team's program on Opening Day it makes us take notice, causing us to link said age to a team's eventual accomplishments. In the case of Keri's piece, his overall point that older teams need to think about the future with more concern than teams with a lower average age makes sense, but let's not forget that a club's age makes up much less of a team's success than we first thought.