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How Will Chase Utley Age?

The Phillies got some bad news over the weekend, as Chase Utley‘s lingering knee soreness resulted in him getting an MRI. While no structural damage was found, you can now add his knees to the ever-growing list of body parts that the 32-year-old has had problems with. As noted in the linked article, he had surgery for a broken hand in 2007, hip surgery following the 2008 season, and then had to undergo surgery on his thumb last summer.

From the quantity of health problems he’s had in the last four years, it might appear that Utley’s body is just beginning to break down. Given that there are a number of examples of second baseman who fell off a cliff in their early 30s – see Roberto Alomar, Carlos Baerga, Chuck Knoblauch, and Brian Roberts, among others – it could be natural to assume that Utley’s headed for a steep decline. In fact, the rate of aging among second baseman has been so severe that it has become a truism in baseball that players who man the keystone position simply don’t age well. Theories on the causes of this phenomenon often hinge around the beating second baseman can take while turning the double play, as they often have to guard the bag with their back to an oncoming baserunner intent on breaking up the twin killing. Is Utley yet another example of the wear and tear of second base causing a premium second baseman to break down earlier than he would have otherwise?

I’m not so sure. Instead, I’m wondering if our perceptions of early declines from second baseman aren’t actually the result of selection bias. It’s no secret that most second baseman are players who, for one reason or another, were determined to be physically incapable of staying at shortstop. Often the problem is a lack of arm strength, but you also see guys with below average range at short getting moved to second base where their defensive issues won’t be so exposed. Either way, second base is mostly a land of players who have already been deemed to be less than top-shelf physical specimens, and as such, it’s a position that generally doesn’t have many truly elite players manning the position.

Look through the list of best individual second base seasons in the last 50 years – with the exception of Joe Morgan (who dominates the top of the list), there just aren’t many other names who have multiple 7+ WAR seasons. Here’s the list of guys who have had more than one season at that level:

Joe Morgan: 5
Chase Utley: 4
Bobby Grich: 3
Ryne Sandberg: 2
Bret Boone: 2
Jeff Kent: 2

Boone’s the odd duck who doesn’t fit here. He was essentially a nothing player through age 31, then had two monster seasons at 32 and 34. His career-arc was nothing like the others, so we’ll toss him out as not that instructive of a comparison. How did the other four guys age?

Sandberg fits the narrative, as you can see his line flatten out after his age 32 season – after posting a +7.6 WAR season that year, he compiled just +7.4 WAR total from age 33-37. He’s another example of a second baseman declining early, but it wasn’t injuries that took him out, but fluctuating desire on whether to keep playing. His semi-retirement after the 1994 season makes his latter years a mediocre comparison, as we don’t know how he would have performed had he not pulled a Brett Favre. The other three actually stayed rather productive.

Kent (Ages 32-40): +39.0 WAR
Morgan (Ages 32-40): +37.8 WAR
Grich (Ages 32-37): +23.3 WAR

If we lower the bar to guys who had multiple 6+ WAR seasons, that introduces a few more of the early decline guys like Knoblauch and Alomar, but we also find Rod Carew, Craig Biggio, and Lou Whitaker, all of whom were highly productive players in their mid-30s. While it could still be true that the physical toll of playing second base does cause players at the position to break down faster, we see something of a different story if we limit ourselves to just looking at players who were truly elite players in their prime to begin with.

My guess is that what is perceived as premature aging at the position is really just decline from a lower pedestal to begin with. Since second baseman are primarily selected based on a flaw in their physical abilities, I’m not all that surprised that the general population of those players would contain guys whose bodies didn’t hold up as long as those at other positions. Utley’s not just a normal second baseman, however, and when we look at how the few premium talents at the keystone position performed, we don’t find the same kind of early-30s collapse that is regularly associated with the positional aging curve.

Utley is┬ánot as good as Morgan was, and Kent’s late-career success would look like the exception at almost any position, but I’m not ready to throw Utley into the Alomar/Sandberg bin just yet. Yes, the aches and pains are starting to add up, but a broken thumb is not the kind of injury you expect to be a lingering problem, and his 2007 problem was caused by getting hit by a pitch. The nagging hip and knee pains are problematic, certainly, but given that he was still an elite player with both problems last year, I don’t think we can claim that either has demonstrated enough severity to cause his skills to diminish all that quickly.

Will Utley average 150 games per year going forward? I’d call that unlikely at best, but the Phillies shouldn’t be too overly worried that he’s going to stop producing when he is on the field. It’s quite possible that they won’t get any more +7 WAR seasons from their second baseman, but there is enough precedent to suggest that he can still be quite useful for many years to come.