“It is impossible — at least within the rules as they relate to performance-enhancing drugs — for a ballplayer to be as fast-firing at 37 as he was in his mid-20’s,” argues the New York Times Magazine’s Michael Sokolove, who has the uncomfortable task of tackling the declining output players in their late ’30’s, Derek Jeter in particular.  With the Yankee Captain’s return to the lineup far from determined, Sokolove cites an especially exasperating 15 inning game against Baltimore this past May.

He came to bat seven times, and in six of those he hit ground balls — two of which squirted through the infield for base hits. He struck out in his other plate appearance. He leads all of baseball, by a wide margin, in his ratio of ground balls to balls lifted in the air, an arcane but telling statistic. Jeter can no longer consistently bring the bat through the hitting zone at the proper moment, and with enough authority, to hit line drives into the outfield gaps or fly balls that clear the fences. (Think of that classic advice to Little League hitters: Swing the bat as if you’re mad at the ball! Jeter swings as if he’s mad at the ground, with an abbreviated, downward stroke that pounds ball after ball into the turf.)

The mythology is that old-time players, who did not lift weights and knew nothing about nutrition, had mercilessly short careers. And that today’s players, who condition themselves year-round — often with the help of private trainers, the most up-to-date scientific methods, nutritionists and massage therapists — play longer and have more years of peak performance. It makes sense. It’s also not true.

With more rigorous drug testing, a typical baseball career is beginning to look again as it did throughout the game’s history. Journeymen players stay in the game until their early- or mid-30s, and all-star-level players maybe a couple of years beyond that. A handful of superstars retain enough skills to make significant contributions into their late 30s. Those with the most talent almost certainly lose their skills at the same rate as lesser players, but they stay in the game for a long time because 85 percent of a superstar is still a very good player.