Appreciating a core of peak-age players


When the Yankees closed out the 2008 season, youth was not on their side. The team had just two regulars — Robinson Cano and Melky Cabrera — on the right side of 32, and four of their key starters still under contract for 2009 were going to be playing their age 35 seasons. The team needed to get younger and get their quickly.

Since missing the playoffs that year, though, Brian Cashman has built up a World Series Championship that features a solid core of young players who are all enjoying or are about to hit their peak performance seasons. He has replaced some late-30s players with some late-20s guys, and the team should enjoy these peak years as their veterans begin inevitable declines. At the risk of sounding too hyperbolic, the timing couldn’t have been better.

In 2010, the Yankees should expect more of the same. Robinson Cano will be playing his age 27 season and Mark Teixeira his age 30 season. In the outfield, Nick Swisher will be baseball aged 29 this year and Curtis Granderson 28. The the tail end of the peak-age spectrum is Nick Johnson, who will be playing his age 31 season. With Derek Jeter nearing his 36th birthday, A-Rod pushing approaching 35 and Jorge Posada playing his age 38 season, the Yankees will be turning to the young guys for more and more production.

So what do all of these age-related numbers mean for the Yankees? For a long time, the accepted baseball knowledge held age 27 to a peak performance years for most players. Some can sustain that peak for a few years; others can’t. Generally, well above-average players will remain above-average players even throughout their mid-to-late 30s while some see precipitous declines. In either event, good teams will feature a mix of seasoned veterans on the way out and younger players on the way up.

Lately, though, a new study by J.C. Bradbury has challenged those assumptions. The Sabernomics scribe wrote about his findings at length for Baseball Prospectus earlier this week. Basically, he found that players seem to peak at age 29, two years later than previously expected, and that some skills mature later than others and some earlier. For hitters, Bradbury’s table looks like this:

Metric Age
Linear Weights 29.4
OBP 30
SLG 28.6
AVG 28.4
Walk Rate 32.3
XBH Rate 28.3
HR Rate 29.9

The Yankees, then, should enjoy some very good years from their core of youngsters. Nick Swisher and Curtis Granderson are amidst their peak years while Mark Teixeira is sitting on the cusp. Nick Johnson’s stellar walk rate could increase even more, but the true guy to watch is Robinson Cano. After a bad 2008, Cano bounced back with a stellar 2009. He hit .320/.352/.520 with 25 home runs, 48 doubles and a pair of triples. Not yet at his peak, Cano reached career highs in all of his counting stats and neared career highs in his rate stats. He should only get better.

Throughout the mid-2000s, the Yanks turned into a team with aging superstars. They saw Gary Sheffield and Bobby Abreu arrive past their peak years. They witnessed Jason Giambi turn into a mid-30s pumpkin and then back into a slugger, and they watched Hideki Matsui‘s knees crumble. For 2010, at least, age is finally on the Yanks’ side, and if all goes according to plan, the Yankees will enjoy the benefits of youth.

Categories : Analysis


  1. Russell NY says:

    Good post, really enjoyed this one.

  2. radnom says:

    Lately, though, a new study by J.C. Bradbury has challenged those assumptions.

    The article is behind a subscriber wall, but does he make it clear over what time period the data is from?

    I ask because the last 20 years, while most relevant, are also surely influenced by higher levels of PED usage than we have today (although how much higher is impossible to know).

    • The Honorable Congressman Mondesi says:

      But steroids don’t improve performance, they just improve health.

      (making wanking motion in the air with hand)

    • Is it? I thought it was not. Sorry about this. Here’s his statement on the sample:

      I used an 86 years of baseball performance data from 1921 through 2006 to produce a large sample for generating estimates. The historical sample also allowed me to compare how player aging may have changed over the several decades.

      In order to see how players improve and decline with age, it’s necessary to use players with sufficiently long careers to quantify age changes. I included players who played at least ten seasons with a minimum of 5,000 career plate appearances for hitters, and 4,000 career batters faced for pitcher. Each season, a player must have at least 300 plate appearances, and 200 batters faced for pitchers. Furthermore, because when players begin and end their careers is not random—good players tend to start earlier and end later than inferior players—I only looked at player performances from the ages of 24 to 35, even though careers extend beyond this range.

      A potential problem with the sample is that the restrictions that allow players to be tracked over a long period of time mean that I am using a cohort of good baseball players. If good players age differently from bad players, then the results might not be applicable beyond this group. However, as I detail below, aging does not appear to be correlated with performance and the results do not change when I lessen the restrictions for inclusion in the study.

      The PED influence is a problem, but we still don’t really know what the real effects of PED use are on performance. Is it more power, better health, something else? I’m comfortable saying that they don’t help OBP/walk rates or the ability to make contact though.

      • radnom says:

        Well that is the problem with introducing PED’s into any conversation, isn’t it? Not only are we not sure who is doing what, but we can only guess as to what advantage it gained by using in the first place. It was my understanding that certain PEDs do allow the human body to keep producing muscle when age would otherwise start to shut things down.

        In this case there are more factors to consider than just PED’s. I’m sure that advances in health/training have made a baseball player’s peak ages a moving target from the 20′s to today.

      • The Honorable Congressman Mondesi says:

        “The PED influence is a problem, but we still don’t really know what the real effects of PED use are on performance. Is it more power, better health, something else? I’m comfortable saying that they don’t help OBP/walk rates or the ability to make contact though.”

        I’m not comfortable saying that at all. If steroids make a player stronger, I would assume that would improve (or, at least, delay the degradation of) that player’s bat-speed. If the player’s bat-speed improves or just doesn’t degrade, I’d think he’d probably have an easier time making contact, and be able to be more selective about which pitches at which to swing since he wouldn’t have to be as amped up to pick out a particular pitch and maybe start cheating a bit and swinging earlier, than the player who hasn’t received those benefits. I don’t see why we’d be comfortable thinking steroid use doesn’t affect OBP/walk rates, I think the opposite is probably true. They don’t change the player’s mind or feel for the game, but they certainly change the tools the player has at his disposal and how he can use those tools.

  3. Ross says:

    The Yankees’ roster construction gets better and better each year.

  4. Rose says:

    The only scary thing is that we’ll have to do this all over again in a few years when some of these big contracts come to an end…although the chances that lightning strikes twice isn’t that good. We’ll also be signing Jeter to an extension of at least 4 years (into his 40′s), we’ll have Arod into his 40′s, we’ll have Teixeira in his mid-late 30′s, we’ll have AJ Burnett into his mid-late 30′s, we’ll have Sabathia (unless he opts out) into his mid-late 30′s, and we’ll seemingly have to try and get young again quickly.

    Is this bad? Not really…but the Red Sox seem to have a nice formula down for the future. No long term contracts…a fairly decent team…with PLENTY of money to spare if, say, Albert Pujols and/or Joe Mauer becomes available…or anybody else for that matter.

    Meanwhile, we not only have a lot of money tied up…but quite a few important positions as well.

    Is this the end of the world? Absolutely not…but it does make some, at least slightly, worried.

    • A.D. says:

      with PLENTY of money to spare if, say, Albert Pujols and/or Joe Mauer becomes available…

      Well they’d have to offer these guys contracts into their mid to late 30s (at least) to sign them.

      No long term contracts…a fairly decent team…

      Given they aren’t that young, they need to find talented players to play SS, 3B, C, DH, RF, CF/LF & SP as these contracts do expire. There’s usually talent available in every FA class, but its going to be expensive for the good stuff.

      So its a double edged sword, its nice to have flexibility, but its nice to have top talent under contract so you don’t have to go and find it. Luckily for the Yanks the players that are under contract into their 40s are 2 of the best of the game, otherwise personally, I’m fine signing top players with contracts expiring in mid-30s

    • Reggie C. says:

      The Yankees can’t sign everyone. If Pujols never comes to terms with the Cards, he becomes the biggest FA landing ever. No way the Yankees are players in the Pujols market. We’d just have to hope that a superstar hungry team like the Mets or Orioles would have enough freed up cash to compete with the RS.

      As long as the younger Yankees core of Cano, Granderson, Swisher, and yes… Teixiera continue to execute their full potential, and in Granderson’s case improves batting splits, we’re fine offensively in the long run.

    • mryankee says:

      They have to replace Beckett and Vmart if they leave via FA. They also will have to replace Cameron and Varitek. These are not players easily replaced. I am not sure of what great young players they have in their farm system.

  5. Evilest Empire says:

    I read another post by Bradbury on a player’s peak age being 29 a month or so ago, and I remember the statement was beaten up to a bloody pulp by other respected members of the SABR community such as Tom Tango. They all insist the most typical peak age is 27.

    If I recall correctly, one of the major flaws of Bradbury’s study is that he based his numbers on player careers from ages 25 – 35, and this somehow slanted the results. I don’t remember the entire argument for or against, but I do clearly remember the general consensus is that its age 27.

    Here’s a nifty THT post that retorts that aforementioned Bradbury post:


  6. I bet the SLG/XBH/HR peak being 28-29 and the OBP/Walk peak being 30-32 are related to each other.

    Age 27-30 you build your stardom through hitting the ball hard. Pitchers challenge you, and if you’re good enough, you win.

    Age 30-33, after you’ve already established that you’re an elite power hitter, pitchers challenge you less and start pitching around you/walking you more. They give you less to hit, so your power may decline a little, but you’re getting more free passes because you’re an established offensive force.

    • Rose says:

      So Mauer has a nice couple years left before they start pitching around him lol

      /playfully facetious

    • Ed says:

      I think that’s some of it.

      I also think as players age, they become more selective in the pitches they swing at. As you start to lose bat speed, your hitting sweet spot shrinks a little. Less than ideal pitches that you used to be able to drive now get fouled off, and pitches you used to foul off now get missed. You can compensate for this a little bit by swinging at less pitches and taking more walks. Eventually your skills decline enough that you can’t hit pitches you really should be able to hit, and you start making more outs.

  7. mryankee says:

    Why would the Yankees not be players for Pujols or Mauer? I do not think you let those guys go at FA. I would think the Yankees would be lining up to get one or two.

  8. Riddering says:

    In three years, Nick Swisher will only have PAs (not ABs) and they will all be walks.

  9. Bo says:

    If they actually had a decent or even average farm system from 98-2005 this wouldnt even be an issue right now or the past 5 yrs. The disaster that was the farm system hurt the whole past decade. This team is lucky they didnt bottom out like Mets. They wouldnt have had to reach for over 35 yr old players. Wouldnt have had to give extra yrs to average sp’s. Would have spared all of us the sight of Tony Womack.

    The whole key to success is to have a fertile system. Overflowing with talent you can either use for your team ie Cano or use to trade for in their prime players like Granderson.

    That is why the whole industry is now deathly afraid of the Yankees. its not because they can give out big deals. That helps. its that they finally realize that having a strong, deep system is key.

  10. Mo says:

    Why not make a trade for a young LF. Rajai Davis 29, Chase Headley 25, Dexter Fowler 23. They can all be had for some package of young talent. Davis and Fowler would work well as a platoon for Gardner fans. Any of those players will certainly cost prospects but they are young with ML experience and under salary control. I can see Chase Headley being a Yankee OF for 10 years.

    • Any of those players will certainly cost prospects but they are young with ML experience and under salary control.

      So then why would the team with control give them up in a trade? The Yanks would have to overpay right there.

      • Mo says:

        Carlos Quentin, Nate McLouth, Jeff Francouer, Nyjer Morgan young OF all traded.

        Maybe because the other team has a surplus in OF and the Yanks have surplus prospects at say pitcher and catcher (No, not Montero).

  11. Mo says:

    Carlos Quesntin, Nate McLOuth, Jeff Francouer, Nyjer Morgan young OF all traded. Cashman was not interested in any of them. I loved his trades for Gransy and Swish and I would love to see hime make a trade for a similar LF keeping Gardner as a 4th OF. For all the sabermetricians, how do you calculate Gardner’s value or WAR as a pinch runner when he can be strategically pulled off the bench and placed in scoring position or on first and put himself in scoring position? There must be some value over him hitting ninth and not having a PR for Johnson, Swisher, or Posada close and late.

    • Steve H says:

      How would you possibly know who Cashman was or wasn’t interested in?

      • Mo says:

        I don’t know. I’m hoping.
        maybe he passed for good reasons. However, Joel Sherman revealed yesterday that the Yanks had a deal in place for MIke Cameron last summer.That is not the deal I want to see the Yanks make, it seemed McLouth went real cheap last summer. I would love to see him bring another young and more athletic more versatile OF via trade.

        • Wait. The deal you don’t want to see the Yanks make is one that would have brought back one of the best fielder CFers in the game and a guy who is definitely better than most of the players you’ve listed so far? And one who was only under contract for a few months and wouldn’t have hamstrung the Yanks? That does not make sense to me.

          It’s illogical to argue that the Yanks should have gotten Jeff Francoeur while saying you didn’t want to see them trade for Mike Cameron.

  12. Mo says:

    Who was the last Yankee prospect that you regret seeing the Yanks trade. Roberto Kelly for Paul O’Neill? George Costanza’s father Frank is still heated about trading Jay Buhner.

  13. Mo says:

    Mark Teahen 28 was just traded he would have been a good Yankee lf, rf, 3b. Esentially a younger cheaper DeRosa. His swing would also work in a stacked lineup at YS3.

  14. Juke Early says:

    I know this won’t change anybody here’s mind & I know you guys gotta fill space(?). But if people can keep grinding these numbers out, I can keep making the same observation. All this bookkeeping & their ancillary puffery take the fun out baseball. It reminds me of accounting. Are most baseball writers accountants now? I guess its somebody’s idea of entertainment / reportage. It ain’t mine. Too much media BS. Throw the ball, hit the ball, catch the ball.

  15. Davor says:

    Well, J.C.’s study says that predominantly healthy above-average player will peak around age 29. It has its uses, but not predictive one. Basically, it says that, if he hadn’t been injured, Bernie Williams would be one of the best CF’s in 2004 and 2005.
    As MGL has found in his study, players who had at least 10 years in Majors and at least 5000 PAs peak between 29 and 30 and have more gradual decline afterward than classic age studies predict.
    These studies are relevant as predictions only if you have some reason to believe that player in question has less than average susceptibility to normal, “aging” injury (“wear and tear”) and won’t suffer serious freak injury (collision, freak fall…), and has above-average true talent level.

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