ROBBIE Alomar was a sure-shot Hall of Famer until he came to New York and got old faster than Jose Reyes goes first to third. Must be our air, or the cynicism in it, that suddenly has taken four miles an hour off Randy Johnson’s fastball.

There is no fountain of baseball youth in this town, where even oldies formats can suddenly be deemed passe and the media always has a new wrinkle to put on even the most accomplished player. If you can no longer lift one of our teams that probably has seen better days, we’ll put your Cooperstown credentials in a wheelchair and heartlessly roll them off a bridge.

Oh, Johnson, one of the most dominant left-handers of all time, isn’t going to disappear from too many first ballots, even if he finishes up here as the shadow of himself that, well, don’t most of them wind up?

But here was the eighth-winningest left-hander in history on the mound yesterday at Shea still having to guarantee an enshrinement that looked virtually certain upon his arrival here for the 2003 season.

On this day, Tom Glavine, the new, improved, old version of him, looked again like a lock in scattering nine Giants hits in 72/3 innings, winning for the fourth time this year and the 266th time in a career that contains two Cy Young Awards, one World Series MVP, and nine All-Star selections.

Sounds like plenty to get him on 75 percent of the writers’ ballots, but 287 wins and one of the game’s best strikeout totals still leaves Bert Blyleven with his nose pressed against the Cooperstown glass, where it likely will remain. So Glavine (266-176) needs a lot more days like this one, in addition to 200 innings this year to guarantee the 2006 option of a contract that was designed to get him closer to the magic 300 than it will.

Glavine, who could have gone to Philadelphia or stayed with the Braves, didn’t figure into the equation, with Roger Cedeno as an everyday outfielder, Mike Piazza as a first baseman, the dreaded Ques-Tec, and, after appearing to be back to his old self at the All-Star break a year ago, a terrible team behind him.

This season began with one of the game’s all-time locators being unable to locate. But to the surprise of a lot of people besides Willie Randolph, mechanical adjustments have led to more strikes, more confidence and, amazing how this works, fewer dunkers finding space between fielders with men on base.

“Earlier, I was only hoping things would come together and it’s tough to execute when you are just hoping instead of knowing,” Glavine said.

Glavine, surrendering more than two runs in one of his past five starts, is getting soft fly balls of yore and, yesterday, got love from the fans when he was relieved. He gets no credit from these people for what he did in Atlanta, often to the Mets, in fact. But in his third New York season, here are the Mets tentatively in a division race, just as Glavine had expected, with finally enough defense behind him to give him a shot at the ultimate goal in pitching.

Nine more victories this year, not a reach, would get him to 275 and within reach of 300, starting a 19th season at age 40.

“It’s still a distant goal,” Glavine said. “At the end of this year, I’ll reassess.

“If I get to the point where over two years I need 12 or 13 wins each year to do it, I think it’s realistic. I will need an extra year, but if I continue to feel the way I do now, it’s not out of the question.”

At least it has resumed being one. A day like yesterday, one could even dream how nice it would be for him to do it here.