Roughly two years ago at this time, most observers were speculating about how the Yankees were going to get out of Jorge Posada’s contract. Posada had had a poor year by his standards, batting .251 AVG/.339 OBA/.411 SLG through the end of August. If he caught just a minimal number of games in 2006, his 2007 contract would automatically vest. This was regarded as a potential disaster. Most catchers burn out early due to the stresses of their position, and it seemed certain that if the Yankees didn’t find a way to wriggle out of the commitment, they were going to be stuck with their own version of Johnny Bench circa 1982.

It’s fascinating how baseball can give one all the information one needs to come to a conclusion like that — supply you with the evidence in Benches, Yogis, and Piazzas — and yet the answer still comes out wrong. Posada was excellent in 2006, and through Tuesday night, he was batting .340/.423/.546, the best offensive numbers of his career. One of the most urgent tasks for the Yankees this off-season will be re-signing him.

Part of the confusion about Posada results from the fact that the standard models don’t apply: He’s really not like anyone else. In contrast to the always variable race of pitchers, hitters are a fairly predictable lot. You can generalize about the arc of their careers with some accuracy, which, parenthetically, is why the fact that Barry Bonds hit 73 home runs at age 36 is suggestive of illicit substances at work. Players just don’t peak at that age. Except, apparently, in Posada’s case.

But then Posada has always been an odd duck of a hitter. He’s a switch-hitting catcher (unusual in and of itself), and a true switch-hitter at that, not a hitter who is capable of standing on either side of the plate in a desperate attempt to fool his team into thinking he doesn’t need to be platooned. See, for example, the new Yankee Wilson Betemit, who to this point in his career has struggled against left-handed pitching in a way that’s unusual for a true right-handed hitter. Posada has great power and plate judgment but doesn’t hit for high averages. Player projection systems, such as Baseball Prospectus’s PECOTA, that use basis comparisons of common types of players, struggle to find useful analogues to the Yankees catcher. Few hitters, and even fewer catchers, have his precise combination of skills. Thanks to working with Tony Pena, Posada also hit something of a defensive peak last season, catching 38 of 102 attempted base-stealers, or 37%.

That Posada is defying the aging curve is perhaps one of those rare instances of positive cosmic payback. Posada came late to catching, having begun his professional career as a middle infielder, and reached the majors for good at the advanced age of 25, or just two years away from the age at which most hitters peak and begin to go down the other side of the mountain. He then had the misfortune of being stuck behind catcher-cum-coach Joe Girardi, a player more valued for the contributions he made as a receiver and clubhouse presence than those he made at the plate. It was clear from the outset that Posada would easily out-hit Girardi (Posada’s rookie .250/.359/.410 was far beyond Girardi’s meager offensive abilities, even when he played in for the Colorado Rockies). But from Bruce Benedict to Tom Pagnozzi to Girardi, Torre has always preferred one-dimensional, goodfield, no-hit catchers to those actually capable of putting runs on the scoreboard — which is to say that Torre objected to catchers much like himself. Torre had just encouraged the Yankees to dump the popular slugging catcher Mike Stanley for Girardi, and having won that victory wasn’t about to reverse course.

Posada spent three long years as Girardi’s “apprentice.” He apprenticed right through the conventional peak, not receiving 500 at bats in a season until 2000, when he was 28 years old. Even then, with Posada having a breakout .287/.417/.527, 28 home-run season, Torre suppressed his playing time by batting him sixth and seventh in the lineup, a practice Torre has continued in all the years since. Even this year, with Posada contending for the batting title, he’s spent nearly as much time batting sixth as he has fifth, and has batted higher than fifth just twice. If Posada has been granted some borrowed time in what should be the twilight of his career, he’s only making up for the time stolen from him when he was in his 20s.

Now the Yankees are faced with life without Posada. There are no alternatives in the organization, and reserve Jose Molina is an upgrade only in relation to Wil Nieves. No one knows how many years Posada will ask for, but if he were any other catcher, more than a year or two would seem like a stretch. With Posada, though, a longer deal might be justified. In three years he might still be a very useful hitter, not hitting .340, perhaps, but still carrying enough walks and power to be a productive hitter. Given the unusual shape of his career to date, it would be presumptuous to insist that he won’t make good.

Mr. Goldman writes the Pinstriped Bible for yesnetwork.com and is the author of “Forging Genius,” a biography of Casey Stengel.