Nate Silver's riding high these days. One of the founders of Baseball Prospectus, leaders of baseball statistical analysis, Silver created the PECOTA system for predicting future baseball events. Right around this time last year he was saying that the Rays would break out with a big season, which, of course, they did. Shortly after that he moved into the political arena with FiveThirtyEight.com, which analyzed polls and past events to accurately call just about every shift in the electoral tides right up to Barack Obama's election.
So it makes sense to pay attention when he reads the tea leaves. His most recent finding isn't one that's likely to cheer Yankee fans. Silver sees a coming storm for Alex Rodriguez, one that will leave him short of the home run record many have already handed to him and which will make his contract a bloated anchor for a good chunk of the next decade.
The article, which is only available to subscribers of ESPN Insider, notes that Rodriguez has been so productive that it is hard to accurately project where he'll go from here. That said, most players do start heading downhill sometime after their 33rd birthday, Rodriguez turns 34 in July, and it's impossible to assume that A-Rod is any different.
Silver's system offers the most comparable players at each age and it's notable that the top of Rodriguez's list is Sammy Sosa, a player who didn't have much of a career after his Age 35 season. Others on the list were more productive, including Hank Aaron, but the simple fact is that most players don't hit 200 homers after turning 33, let alone the 300 hit by Aaron and Barry Bonds.
While that kind of aging curve may not be likely, it certainly isn't impossible. Rodriguez has never been seriously injured, has never had a truly bad season and, as Silver noted, isn't quite like any other player that's come before him. Past performance may not be an accurate predictor of future success, but there are always outliers. Silver even notes that there's a three in 10 chance that A-Rod beats out Bonds. Time will tell how that plays out, but Silver's prediction is interesting in another way.
The contract that the Yankees gave Rodriguez before 2008 assumed gargantuan production into his 40's. As Silver makes clear, that's a bad bet any way you slice it. After all, as Rodriguez himself admitted, he's human.