The Yankees are fighting for the lead of an American League East that, with the rise of the Toronto Blue Jays, is as competitive as it’s been this decade. This is a plain statement of obvious fact, but it comes as almost a surprise when put that way, given the relentless negativity surrounding the team.

You have to expect that: Because they’re the Yankees, their successes are taken for granted and their failures are treated as morally squalid. A season that sees Randy Johnson collapse, Alex Rodriguez develop what at times appears to be a mental block preventing him from making contact in the clutch, and injuries to Hideki Matsui and Gary Sheffield that could keep them out the rest of the season is of course going to inspire more than the usual wailing, and everyone should understand why.

Still, an extraordinary amount has gone right for the Yankees this year, not in the sense that they’ve had an unusual amount of fluke bounces or good calls, but that several players, some of whom are doing nothing more than what they’ve customarily done, are having seasons much better than they should be having.

I’ve often pointed out the downsides of the Yankees’ focus on veteran stars: Having a roster full of old players makes it more likely that a few key players will be injured or collapse, makes it more difficult to work in farmhands, and so forth.This season the Yankees are showing the upside, which is that when you have a lot of veteran stars you also make it more likely that a few key players will have monster seasons and paper over your flaws.They’re really the only team that could get away with it, but so long as it works, it works.

The best development for the Yanks this season hasn’t even been one of those pricey veterans, though – it’s been Robinson Cano, who in spring training wasn’t even assured of a job on the major league roster because of supposed dissatisfaction with his work ethic. Like his predecessor Alfonso Soriano, Cano isn’t very good at second base and has glaring flaws in his offensive game. Also like Soriano, people spend way too much time picking at those flaws and overlooking how good he is. Cano is 23 and hitting .327. He never walks and he doesn’t hit many home runs, but it’s impossible for even an indifferent defensive middle infielder to hit .327 and not be exceptionally valuable.At this point, with Cano having hit .307 over a season and a half at such a young age, it’s probably time for people to stop griping about what he can’t do and appreciate him for what he can do.

Past Cano, the next-most pleasant surprises have been Mike Mussina and Jason Giambi, both of whom are fully healthy for the first time in a couple of years and putting up monster seasons right out of their primes. Likely because his tenure in the Bronx hasn’t coincided with any championships, Mussina has never been respected as he deserves,but over the course of his Yankees career he’s quietly been one of the better freeagent signings of all time – a big game pitcher who could easily have won Cy Young awards in 2001 and 2003 and at his worst has been good for 170 innings of league average baseball. It would be nice to see him finally win 20 after being written off as all washed up.

Giambi, for a variety of reasons, will never be as respected as a guy who consistently gets on base 43% of the time usually is, but he’s been the engine of the Yankees’ offense this season, and in retrospect his deal, too, looks a much better investment than it seemed at the time.

The players who have kept the Yankees at the top, though, are the same ones who have done so all these years: Derek Jeter, Mariano Rivera, and Jorge Posada. You can’t say with a straight face that Jeter and Rivera are underappreciated, but as legendary as their performance at crucial moments has become (the odd blown save against an awful Nationals team aside), the sheer unlikeliness of their sustained day-to-day excellence is often taken too much for granted.

Jeter, hard as it is to believe, is no longer a young player or particularly close to it; he turns 32 in a few weeks,advanced middle age for a shortstop, and he’s hitting .341 through injury, his short inside-out stroke seemingly unaffected by time. Rivera is doing what he always does, as he has for 10 years – much longer than any closer in history who’s been used comparably has been able to do it. And Posada has snapped back to MVP form after the first down season he’s had since becoming a regular had people wanting to get rid of him in favor of the awful Bengie Molina.

It’s not normal for a 35-year-old catcher to put up a .416 on base average, for a top closer to go a decade without an off-year, or for a 32-year-old at any position, let alone shortstop, to hit .341. These kinds of extraordinary performances, to which New York fans have become so accustomed, create the context within which perfectly normal occurrences like Randy Johnson losing it at 43 or Alex Rodriguez not being a character out of a video game but a real live player with a hole in his armor seem unusual.

It’s a tight race, and outside the players mentioned here, Johnny Damon, and a couple of relievers, there aren’t many Yankees doing much of anything. With their young pitching and clever management, I like Boston to create some space in the division during the next few weeks.But if the Yankees finally go down this year, at least the handful of players who have held them up through so many disastrously stupid decisions over the last few years will go down having done their part, just as they always have.

tmarchman@nysun.com