I keep saying I’ll keep these brief, then writing really long posts. This one I promise I’ll actually keep brief.

The Major League third basemen in April: David Wright, Fernando Tatis.

Overview: David Wright had, for him, a down season in 2009. Just about everyone who has ever seen a baseball game, and seemingly many people who haven’t, has some guess why it happened. It was the ballpark. It was the pressure. It was Tony Bernazard’s opposite-field approach. It was the lineup around him. It was his mechanics.

Who knows? Who cares? Last season was last season. As my colleague Mike Salfino pointed out last month, single-season fluctuations like the one Wright endured in 2009 are not unheard of for superstar players. Check out Mike Schmidt’s 1978, for example.

And the good news is that a bad year for Wright is still an awesome year for a regular Major Leaguer. Wright’s power output dipped and his strikeout total spiked, but he still got on base at a .390 clip.

Whatever leech sucked out Wright’s home-run power apparently also sapped up his ability to defend at third base in 2009, thrilling talk-radio types who’ve been saying for years that he wouldn’t last at the position. After two straight seasons of positive defensive contributions, as measured by both UZR and +/-, Wright fell to last among qualifiers in UZR and 33rd in +/- in 2010.

It was, undoubtedly, a weird year for the Mets’ young star. Here’s the thing, though: Don’t bet on any of it to continue. Superstars don’t become superstars by rolling over in the face of adversity, and I’ll wager David Wright spent his offseason doing everything in his power to correct whatever ailed him in 2009.

The gun show he gave the New York Post early this spring? Part of that, I’m certain.

Wright will bounce back in 2010. Mark that down.

The Major League third basemen in September: Wright, Tatis.

Duh.

How they stack up: Wright is better than Placido Polanco and Jorge Cantu. It’s very hard to bet against Chipper Jones, but Larry had a down year at the plate last year, has a history of injury issues, and will be 38 later this month. There’s some chance he’ll return to his Hall of Fame form, stay healthy and hit well enough to outproduce Wright, but I’m not willing to consider that possibility, because frankly, screw that guy.

Ryan Zimmerman played better than Wright did in 2009 on both sides of the ball, and there’s been some buzz around the Internet that he’s now the better overall third baseman. I’m skeptical. Zimmerman’s certainly a better defender, but I find it hard to believe he’s anywhere near as good a hitter as Wright on the strength of one good year. In 2007 and 2008, after all, Zimmerman was little better than league-average at the plate.

Regardless, both young third baseman are great, and since they’re not actually in competition, it doesn’t matter. If Zimmerman again performs like he did in 2009 or continues improving as young players do, and Wright returns to the form he showed in 2007 and 2008, it will take a lengthy debate to determine the N.L. East’s best. And I promised I’d be brief.