The Mets, as much as any other team, are a franchise of traditions. One of their finest is doing the right thing by accident and for the wrong reasons, as when they mysteriously let the White Sox claim Tom Seaver out of the free agent compensation pool in 1984.

This week’s announcement that Aaron Heilman will be pitching out of the bullpen rather than assuming the fifth starter’s role, as had been planned coming into spring training, is another perfect example. It makes the winter trades that saw the Mets deal starting pitching for bullpen help seem somewhat nonsensical in retrospect and leaves a huge hole in the rotation; be that as it may, it’s still the move the Mets needed to make.

One feels for Heilman. Last year, after several seasons in which he’d failed to live up to the promise that made him a first-round draft pick two years in a row, he finally had the kind of success everyone had always foreseen for him: A change in his arm angle added life to his fastball and movement to his change-up, making him one of the best relievers in baseball, with an 0.68 ERA after the All-Star break.

But Heilman wanted to start. He played winter ball to stretch his arm out and, with the Mets having traded Jae Seo and Kris Benson in part to clear a rotation spot for him, came to Florida looking great, with a 1.29 ERA and 11 strikeouts against no walks in 14 innings. He couldn’t have done more since the end of last season to prove he deserved to start, and he ended up in the bullpen anyway.

This only partly has to do with the fine spring enjoyed by 25-year-old rookie Brian Bannister, whose pretty 0.95 ERA in 19 innings shouldn’t obscure the fact that as a soft-tossing righty without truly exceptional command, he’s probably better suited to be a spare starter than a rotation stalwart. But more important is the simple fact that Heilman developed into an elite reliever last year. Certainly, there’s reason to think he could handle an expanded role, but there’s also reason to think he’d be less valuable as a starter than as a reliever, and the basic logic here is sound.

Knowing the rotation will probably be weak in one way or another – at the very least, it won’t be going very deep into most games – the Mets are going to make the bullpen as strong as possible. With Billy Wagner closing, Heilman working in the seventh and eighth innings, and Duaner Sanchez, Jorge Julio, Chad Bradford, and co. on hand to soak up anything before that, this could, and perhaps should, be the deepest and best pen in the game.

All of this makes perfect sense, except for the fact that it only seems to have occurred to Mets officials during the last week. It’s nice that Bannister is showing signs that he can be an adequate fifth starter, but it would be nicer to have Seo, a reliable fourth starter, in the rotation.

It also can’t be good for Heilman’s morale to have done everything possible to prove himself ready for the starting slot the team opened for him and yet still be passed over for it. Whether or not it’s the best thing for the team and for Heilman, more decisiveness one way or the other during the winter would have avoided the prospect of needlessly embittering a valuable young player.

More important than any of this, though, is the Mets’ willingness to change course and essentially admit that they’d been wrong to even entertain taking Heilman out of a role in which he’s been successful. That kind of willingness to admit error and change course is going to be key to the season.

With Bannister in the rotation, Anderson Hernandez at second base, and Xavier Nady and Victor Diaz vying for playing time in the outfield, there are many young players with some strengths and some weaknesses to whom the team shouldn’t make any kind of real commitment. When ego and stubbornness get involved, though, it can be difficult to correct a choice like the one to give Hernandez the second base job, should it become necessary. The Heilman move is good reason to think that won’t be as much of a concern for the Mets as it so often is for other teams.(Just think of Tony Womack, left fielder.)

The Minaya/Randolph Mets are still a lot newer than they seem. This is only their second year, though the Jim Duquette administration seems like it dried up and blew away a decade ago. Jokes about Mets tradition aside, this administration has shown little of the rigidity that has been the team’s worst vice at several critical points in its history. We’re still figuring out exactly what they’re all about, but both on its own merits and for what this maneuver says about the way the team will be run more broadly, this decision should make even the most anxiety-plagued fan a bit calmer.

tmarchman@nysun.com