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Your Favorite Player Is Slightly Younger Than You Thought

Nick Swisher, spring chicken.

Those of us who count the days until the new edition of the Baseball Prospectus book comes out — just a little more than a month away — have been long familiar with the sabermetric axiom that baseball players peak around the age of 27. Doesn’t that seem a little young to you? That always seemed a little young to us. Anyway, over the weekend, the author of The Baseball Economist might have definitively proven the old axiom wrong.

Proven it wrong in a polite, mathematical, nerdy way, of course, because this is BP, and BP is the best. J.C. Bradbury argues that the peak age is 29, and he’s certainly convincing.

There are all kinds of fancy charts and formulas and so on, but here’s all you really need to know:


Player skills peak at different times, often quite far apart from each other. Hitters peak in batting and slugging average at 28 while continuing to improve in their home-run hitting and walking abilities until 30 and 32, respectively. Home runs rising beyond the peak for doubles and triples indicates that foot-speed on the basepaths fades before hitting power. In addition, batters may be using veteran knowledge to better manage the strike-zone — or possibly becoming more friendly with umpires — to walk more and hit with power as they age. Pitcher strikeout ability peaks around 24, while walk prevention peaks nine years later. Again, veteran know-how appears to be playing a role in improving performance to compensate for diminishing physical skills.

So, how can you apply this to your daily fandom? Well, it means David Wright is entering his peak year right now, and Nick Swisher just went from past his prime to smack in the middle of it. (Did you realize Swisher is older than Curtis Granderson?) It could affect the way contracts are structured — for example, Albert Pujols reaches his peak on Saturday, when he turns 30, as opposed to two years ago, making him more valuable when he becomes a free agent. (Assuming, of course, Albert is actually 30.) And it makes the Yankees younger than they were a year ago, if that makes sense. If you dig deep into the whole matter, it can change the entire way you think about baseball, about your team — about all of it. They have more time than they thought they did.

And for those of us who are 34 years old in the real, non-baseball world, it makes us feel infinitesimally younger. We have the exact same birth date as new Phillies third baseman Placido Polanco, who is now a tiny bit less of a veteran. Whatever gets us through the night.

Jamie Moyer is still 94, however.

Your Favorite Player Is Slightly Younger Than You Thought