Adding up in simple terms, Luke came up with +5 -8 =2, for the guys who had the best age-35 years, in their following age-36 seasons.  A few reactions:

(1) There's some tendency for the infielders-with-power, the guys with small frames who hit the ball hard, to cluster in the disappointing area.

(2) Age 36 is very, very old for a baseball player.  No doubts there.

(3)  John Benson Rule:  A player is who he was when we last saw him, meaning, late last year.  Nelson Cruz again finished very strongly, slugging .571 over the second half - despite injuries.  

Bet you there'd be some tendency for the Werth-Rollins list to fade a bit in their age-35 years... let's check it out.  Was there any tendency for this "dropoff" list to telegraph a DWN season with a fade in the second half?

....

VICTOR MARTINEZ:  Wait.  First thing to note is that he bounced back at age 37 (this year) to hit at historical norms.  That don't count, do it?.  We're talking about whether people lose their ability to hit permanently.

Anyway, in V-Mart's age 35 season he did drop off majorly in the second half.  He had hit .305 with a .514 slug in the first half of his age-35 season, but sank to .269 with a .426 SLG as he hit the second half.  Then he had that DWN age-36 season, but a good age-37 season.

....

JAYSON WERTH:  Two names in, Dr. D is feeling very good about Boomstick.  Is 'cuz Jayson Werth was never my idea of a super talented hitter; not sure how he surfaced on this list.  Anyway, Werth did NOT sink in his age-35 second half; he got a little better.  Then he hit the wall at age 36.  Surprising to me that this player did not hit the wall at age 32.  That's when ballplayers turn horse manure, age 32 or age 33, unless they're Nelson Cruz.

....

SCOTT ROLEN:  His last All-Star season was certainly at age 35.  He faded badly in the second half of that season, going from a .548 SLG in the first half to a .420 SLG in the second.  That's 17 homers at the break and three after.  

Valid comp to Cruz at the plate.  But again Dr. D is pleasantly surprised, because Rolen telegraphed his crash, certainly, and Nelson Cruz was awesome when we last saw him.  Including in the last coupla games we saw him.

....

JUAN URIBE:  I ain't doin' this.  Uribe's lifetime OPS+ is 87.  Neither are we gonna compare Steph Curry to Richard Sherman.

Uribe showed up on Luke's fine list because of a high WAR total that year.  That's fine, but my own thread is doing something a little different:  thinking about Nelson Cruz' likelihood of 30 dings and 90 RBI next year.

For the record, Uribe didn't fade in the second half of his age-35 season.

....

JIMMY ROLLINS:  5'7", 175 lbs.  At age 33-34, his OPS+ was in the 90's; at age 35 it was 100 exactly; at age 36 it was about 80.  "FILTER."

Before I started this, I shoulda acknowledged P-I's use of the WAR stat in compiling these lists.  Which is very cool, but.  There's a difference between soft-skills WAR heroes like Chone Figgins and hard-RBI WAR players.  That distinction is my own; I'm free to make it and it doesn't reflect on the earlier list.

....

CARLOS LEE:  Now we're talkin'.  About thick-chested mashers, that is.

But ... whaaaa?  He hadn't slugged anywhere near .500 since age 33.   ... ?!   Which is where you expect a player of Lee's quality to decline.

....

OK, at this point Dr. D is belatedly realizing that he's been talking apples and oranges... Chase Utley we ain't gonna look up on Uribe-Rollins grounds.

Mark Teixeira is the last guy and he's a really good one; he slugged .548 in his age-35 season and then fell off the table the next year (THIS year).  Did Teixeira fade late in 2015?

He did not fade.  Well ... actually he was only able to play 28 games in the second half of his age-35 season, so yeah, he did.  He hit gret in July (.724 SLG!) but slugged only .333 in a shortened August and then could not play in September.  The next year he was horse manure.  So, it's up to you whether you consider that a telegraph...

...

Now we go back to the top of the list of age-35 players, David Ortiz, Adrian Beltre and Co, guys who played well for years after age 35.

Not calling this a "study," and not submitting it to ncbi.nmh.org for peer review, and factoring in human intuition a quick look kinda leaves Dr. D in this spot:

IF A GUY HAS BEEN ONE OF THE TOP CLEANUP HITTERS IN THE GAME FOR YEARS, AND HE JUST FINISHED HIS MID-30'S SEASON WITH A BLAZING HOT PERFORMANCE RIGHT UP TO THE LAST GAME, I LIKE HIS CHANCES FOR THE NEXT SINGLE YEAR.  REALLY WELL.

That's not a guarantee, obviously.  Star players are year to year in their mid 30's, even if they finished strong.  But that finishing strong part, I bet you it's important.

Be Afraid,

Jeff