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Luke Arkins at Prospect Insider does some heavy lifting for us on the Boomstick subject.  Hmmmm... have got it on my iPad but it doesn't show up on the desktop.  Ah, well... hit prospectinsider.com and there's an Oct. 28th article titled "Can the M's get younger and still contend?"

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Coupla first thoughts:  the idea in the Seattle blog-o-sphere, about 5-10 years ago, was to dig up a Hardball Times or Baseball Prospectus piece on aging curves, and refer to that as the "correct" projection for any given player next year.  Famously, the best saber site in the world did this to rip the Boston Red Sox for signing David Ortiz ... in 2010.  :- )

Industry-smoothed aging curves are never going to take away our responsibility to judge players as the individuals that they are.  You want to be aware of what the aging curves are, but you don't get to use them as the end of the discussion, "I've looked up the WAR and the PECOTA, and this is the answer.  Now pipe down.  You're better than that, Shlabotnik."  Which was absolutely, precisely the state of Seattle discussion five years ago.

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My own framework for any old-and-great player is simple.  "He's year to year.  We'll see in April."  But, of course, somebody has to decide whether to cut the man a $14M check...  (actually in this case they don't have to decide that.  But you know.)

Arkins is well aware that he's part of a discussion, not the end of it, and he makes himself a good part of it (IMHO) with the framework he uses.

(1) Let's take the BEST ten or fifteen age-35 seasons lately.  Lately meaning this decade.  That's really cool, because "this decade" means super-refined pregame videos and five 97-MPH relievers a game and all that stuff.

(2) Let's see how they did at age 36.  That's cool too, because it's objective and to the point.

You can see the caveats for yourself ... there's nothing inherently different about 35-year-old seasons vs. 34- or 36-year-old seasons.  You're going to get only about a dozen seasons.  Half or more of those guys will be very unlike Nelson Cruz.  Etc.

But!  It's still the difference between watching ten different 3-minute "samples" of the Presidential debates, and watching none of them.  This isn't a court of law; it's a baseball chat.  Luke's system is plenty good enough to make for an info-taining discussion.

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Sorting by WAR primarily ... we'll circle back around to that in a minute, as it turns out ... Luke found the following 36-year-olds who were pretty much just as good following a huge age-35 season:

Adrian Beltre, Carlos Beltran, David Ortiz, ARod, Torii Hunter.

He found the following 36-year-olds who dropped off some, but who were still quality players:

Marlon Byrd, Lance Berkman.

And he found these 36-year-olds who were big disappointments:

Victor Martinez, Jayson Werth, Scott Rolen* maybe, Juan Uribe, Jimmy Rollins* maybe, Carlos Lee*, Mark Teixeira, Chase Utley.

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Next...