While sportswriters often find it useful to pretend otherwise, major league baseball teams are not run by idiots or blind men. The Yankees’ brass is perfectly aware that improving the team’s center-field defense is the single biggest thing management can do right now to boost the team’s pitching.

The Mets brass is perfectly aware that Mike Cameron, even when not batting .298 AVG/.399 OBA/.536 SLG, as he is this year, is both an excellent ballplayer and one who might be well worth trading, because he’d be more valuable to a team that could play him in center field.

So it’s not too surprising that the two teams were linked together over the last few days in rumors that had them tentatively discussing a trade of Gary Sheffield for Cameron. The rumors apparently had some substance to them, as Joe Torre, unusually, commented on the prospective deal yesterday after some griping from Sheffield.

“We turned down any inquiry about him from the Mets,” the Yankee skipper said. “We said, ‘No, thank you.'”

Notwithstanding such denials, the potential blockbuster will probably continue to be the subject of discussion and debate for quite some time, partly because of the rarity of interborough trading and partly because, at least in theory, this could be the perfect win-win deal, with both teams dealing from strength – offense in the Yankees’ case, defense in the Mets’ – to improve in an exchange of more or less equally valuable players.

A claim that Mike Cameron, a career .250 hitter, is as valuable as Sheffield, a career .298 hitter who finished second in last year’s MVP voting, might be met with a bit of skepticism, but such is the case. Cameron, after all, is an excellent defensive center fielder and an average offensive player, while Sheffield is an average defensive right fielder and an excellent hitter. Because center field is a key defensive position and right field is not, and because Cameron is such a good defender, the two player’s strengths cancel one another out.

Compared to a random Triple-A centerfielder, Cameron’s usual offense is worth about 30 runs and his defense about 20 runs over the course of a season, to judge by various defensive metrics like win shares and Baseball Prospectus’s fielding runs. Compared to a random Triple-A right fielder, Sheffield’s offense is worth around 40 runs, and his defense around 10. This might be a bit generous to Sheffield, who doesn’t really strike the eye as even an average defender, but I think that when you take into account various intangible factors like Sheffield’s superior batting eye and clutch hitting ability, the scales are fairly well balanced.

All of this is on paper, of course. Real baseball games are not won and lost on paper, and Cameron is not worth nearly 50 runs to the 2005 Mets, because he’s not playing center field. No matter how well he plays in right, a right fielder simply doesn’t have the chance to make as many plays as a center fielder does.

Cameron’s offense is also worth quite a lot less when he plays in right, not because he somehow becomes a lesser hitter, but because there’s an opportunity cost involved. Cameron is, essentially, a league-average hitter, and it’s not too difficult to find players who can handle right field while hitting better than league average – some of whom, like Sheffield, can hit quite a lot better.

On the other hand, playing Cameron in right field yields some benefits for the Mets that don’t show up in the box score. The most important of these is that playing next to two center fielders allows Cliff Floyd to cover a lot less ground in left. With Cameron covering right and right center, and Carlos Beltran covering dead center and left center, Floyd can play towards the line, cutting off doubles and ranging into foul territory after fly balls.

Considering Floyd’s vulnerability to injury, just keeping him from running around in the outfield is worth something to the Mets, leave alone the extra balls he’s getting to. There’s also the fact that for a team fielding a flyball staff in Shea Stadium, where fewer balls go over the fence, outfield defense is more valuable than it is in a lot of parks.

For the Yankees, the benefits of moving Sheffield for Cameron are fairly obvious. Cameron would, in center field, be worth about as much to them as Sheffield is now, but the help would be coming in an area where they need it more – preventing runs. The Yankees’ offense is one of the three best in the game right now, every bit as good as the Red Sox’, and not far behind the Orioles’. Swapping Sheffield out for Cameron would make them a bit worse than the Red Sox, but not unbearably so, and the benefit would be worth it.

Cameron’s defense, compared to Bernie Williams’s, is probably worth – conservatively – 20 runs over the course of a season. All the extra fly balls he would snatch up would not only keep runs off the board, but would keep Yankee pitchers from having to throw extra pitches with men on base after seeing catchable pop-ups dropped. The gains are obvious.

That doesn’t mean the trade would solve the Yankees’ problems. Cameron and Sheffield might both be worth about 25 runs over the rest of the season to the Bronx Bombers, and Cameron’s 25 runs might come in a shape that has more value to the team, but there’s a much more obvious way to improve the outfield: Play anyone who isn’t Tony Womack.

Think of it this way: If the Yanks trade for Cameron, play Hideki Matusi in left, and move Womack over to right, there won’t be any net gain. Womack, over a season, is worth about 30 runs less than the random Triple-A right fielder to whom we were comparing Sheffield. Say the Yankees traded for Cleveland’s Casey Blake, who’s hitting a miserable .224/.298/.390 – over the rest of the season, that would probably be worth 15 runs in itself as compared with Womack’s historically putrid .240/.274/.264 line.

Trading Sheffield for Cameron seems a rather roundabout way to get at a marginal improvement when the obvious solution is to get a Blake-equivalent for center field. If the Yankees keep Sheffield in right, play Matsui in left and get a warm body for center – putting Womack on the bench – that will be worth about 15 runs, which is about 15 more than exchanging Sheffield for Cameron would be worth. Even swapping in Bubba Crosby for Womack would do the trick. Sometimes a big, headline-grabbing exchange of stars is a great way to go about improving obvious weaknesses; sometimes, playing Bubba Crosby is a far better one.