The Mets got so good, so fast this year that it’s a bit difficult to think of just how bad they could be. If you look back to the Opening Day roster, though, it’s even more difficult to see how they could be as good as they are.

Coming into the season, one could have been especially confident about only a very few Mets. Pedro Martinez, a 34-year-old starting pitcher with wellknown injury problems and, at times, troubles breaking 85 mph was one of them. David Wright, who’d turned 23 in December, was another. New acquisitions Billy Wagner and Carlos Delgado were known quantities, though old enough that it wasn’t difficult to imagine either or both simply collapsing, Roberto Alomar style; and the ancient Tom Glavine and Steve Trachsel seemed good bets to do more or less what they’ve done. These were, it cannot be overemphasized, the players on whom the team was actually relying. Every single other player on the roster was an open question to a greater or lesser degree.

MVP frontrunner Carlos Beltran? He was largely given a pass for a massively disappointing first season in Shea due to the fact that he’d played through injury, but he spent the first week of the season getting booed by the faithful.Jose Reyes? Many had confidence in him, but he nearly set a major league record for outs made last year. Down the list you can go, but the glaring problems were second base (remember Anderson Hernandez and Kaz Matsui?), right field (remember Victor Diaz?), and the bullpen, where, short of Wagner, there wasn’t a single pitcher you could honestly point to as an evenmoney bet to be particularly effective this year. Not to mention a back of the rotation so unsettled that Jose Lima, of all people, was called up for two different stints as a starter.

Every contending team has a lot of things go right that could have gone wrong. That’s why they’re contenders. But a team that rolls out on Opening Day with neither a starter, nor even a settled platoon, at two key positions and doesn’t have a back end of the rotation or truly reliable bullpen arms past the closer, usually doesn’t even contend, let alone become the most dominant team in the league. It’s easy to say it’s luck and leave it at that — and when you realize that Darren Oliver, currently boasting a 2.09 ERA, was last seen in the majors in 2004 running up a 5.95 mark, it’s tempting to do so — but is there a better explanation?

I think there is. General manager Omar Minaya has been accused many times of being a checkbook executive, simply signing or acquiring the best, most expensive available players and leaving the rest to providence. That doesn’t really fit with the Mets’ situation at the beginning of the year, though.

At each unsettled position, the Mets not only had several credible alternatives, but alternatives who were, broadly, the same sort of player. Redundancies were built in, and for every backup plan there was a backup plan. In right field, for instance, had Xavier Nady not worked out, Victor Diaz, a similar low-OBA, moderate power, indifferent glove sort of player would have gotten a shot; and if Diaz had not worked out, Lastings Milledge would have been waiting behind him.

At second base the options were more constrained, but you still had Hernandez, an excellent glove man; Kazuo Matsui, who deserved one last shot at becoming the player he was in Japan, and Jose Valentin, who of course ended up working out fine. And in the bullpen there were options, too; had Oliver and Chad Bradford not worked out, the likes of Royce Ring and Heath Bell were ready in the minors.

It’s quite possible to imagine the Mets being exactly as good as they are with an entirely different set of role players — Oliver flaming out and Jose Feliciano taking over his spot with equal results, Hernandez staying healthy and providing superb defense and enough offense to keep a spot in the lineup, Diaz staking a claim to an everyday role.That’s not an accident.

If that’s one part of the explanation of why the Mets are so seemingly lucky, the other is that while the likes of Beltran and Reyes may be playing as well as they’re capable, were they playing as badly as could be expected the team would still be good. Last year each was more or less at the bottom end of his range and the Mets still won, and could easily have won 90 games had they had a few more breaks in close games.

This all goes to Minaya’s fundamental strategy, which really resembles Yankees-style checkbook baseball less than it does a better-funded version of what the St. Louis Cardinals have been doing for years, which involves identifying a set of core superstars who are, even at their worst, going to be good players, and opening up the less important spots to competition among a fair-sized pool of players, knowing that even if most do nothing, you only need one to succeed. If the Cardinals don’t have a second baseman, they just keep several similar players around — one of Mark Grudzielanek or Abraham Nunez or Hector Luna is going to do alright, and it’s just a matter of giving each of them a chance to prove it’s him.

As long as you can collect that depth and do a good job of identifying and acquiring star players, it’s a pretty unbeatable philosophy. So yes, of course there’s a lot of luck in Darren Oliver turning into the best reliever in the National League, but Minaya put the team in position to benefit from that luck by gathering up a fair number of pitchers who had similar upsides and letting the fittest survive. It takes some guts, and it only looks easy.

tmarchman@nysun.com