The most famous curse in American sports is the Sports Illustrated cover curse. It happens all the time — some golfer, ballplayer, or football team gets plastered on the cover and within weeks or months everything begins to go horribly wrong. Like any curse, it also has an entirely rational explanation: Anyone so good that they make the cover of Sports Illustrated is probably at the top of their field, and when you’re at the top, the most likely place you’re going is down. It’s so simple, people never even think of it.

This comes to mind when thinking about John Maine, the 25-year-old Mets starter now working on a 23-inning scoreless streak, because the only time a player like Maine gets a lot of attention is when he’s doing something he’s not likely to keep up.Will Maine break Orel Hershiser’s record of 59 consecutive scoreless innings? No. Will he maintain his current 2.08 ERA through September and start Game 1 of the playoffs? Of course not. That’s not so important, though; the reasons he’s succeeding so brilliantly now are the same reasons he should develop into an effective pitcher for the next few years, and if he collects a nice string of game highlights in the process, all to the well.

When Maine came over from Baltimore in the trade for Kris Benson this year, I posited that he would likely be just as good as Benson if stuck in the rotation, for the mundane reason that when in the minors he pitched exactly like a Benson simulacrum. He tossed fewer strikeouts than you’d like to see, a few more walks, plenty of fly balls, and seemed like an overall package that would make him a league-average starter or slightly below in the National League.

Projecting major league performance from minor league performance is always a rough game in which you remember your successes a lot more than your failures, but considering Maine’s salary is around 5% of Benson’s, the odds of getting reasonably similar performance from him made the trade look like a nobrainer, even leaving aside the fetching Mrs. Benson and her big mouth.

Even before turning in a fine Don Drysdale impression, Maine was making the deal look swell. He came over with a reputation as something of a finesse pitcher despite having issued plenty of walks in the minors, but turned out on closer inspection to actually have a good fastball (if a pretty straight one), and to be as reliant on his changeup as you’d expect a Mets starter to be.

In his few starts before going on the disabled list in May, Maine looked to be the sort of pitcher who, when he has the high fastball popping, throws a quality start, and when he doesn’t is liable to get shelled. In all, he seemed like a guy who’d end up winning as many as he lost — not a bad replacement for the miserable Benson and a far sight better than what many teams have in the fourth or fifth slot in the rotation.

Since he’s come back from the DL, Maine hasn’t debuted a new mystery pitch or revealed a hitherto unsuspected 10 mph on his fastball or anything of the sort; his success has been based on the fastball, the changeup, good location, and aggressive strike-throwing. There’s nothing wrong with that, and it’s in fact a good formula to make any pitcher a moderately wealthy man. Still, he’ll have an adjustment to make, one the savvy Mets fan should be on the lookout for if he or she’s harboring any dreams of seeing Maine shut down the Tigers or Yankees in late October.

Maine’s success of late — and this goes back to the early part of the season — has been built around the fly ball. Of his combined flies and grounders, 54% have gone in the air. That’s in line with what he did in the minors, and it’s also a very high number. Of 44 National League ERA qualifiers, just 10 are more likely to give up a ball in the air than on the ground. Of them, most are successful — Pedro Martinez and Jason Schmidt, among other notables, are part of this group — but to some extent that’s a selection effect. Balls in the air can go for home runs, so a pitcher who gives up lots tends to do everything else well.

The point here for Maine is that, nice as it would be to think otherwise, pitchers don’t have an enormous amount of control over whether those high strikes end up settled in an outfielder’s glove or not. Missed spots, wind patterns, bright lights — all sorts of things can work against a pitcher who’s inducing can of corn after can of corn.And that’s exactly what Maine is doing. In his most recent start, for instance, he gave up 11 flies to two ground balls, an absurd and unsustainable rate.

What you’ll see, as word of his fearsome and effective high fastball begins to get around, is that hitters will lay off it, and he’ll either start walking a lot of guys or he’ll have to pitch lower in the strike zone. It’s only after this period of adjustment has come and gone that we’ll be able to tell what was a flukey run of good luck and what was a real and sustainable improvement.

Despite this, Maine’s good run portends nothing but fortune for him. If nothing else, we now know he has the common sense to take advantage of a big yard and an exceptional defensive outfield, something you haven’t been able to say of all similarly talented Mets hurlers over the last couple of years. And there always exists that chance that he really is this good — who knows?

tmarchman@nysun.com