There are some things in baseball that you can’t appreciate until you’ve seen them up close, some of them the sorts of things you know you’ll tell your grandchildren about. Once you’ve seen the speed and violence of the break on Mariano Rivera’s cutter or the level force of Albert Pujols’s swing from field level, you get a visceral sense for just how hard baseball is that nothing else can give you. Watching Ivan Rodriguez warm up his arm before a game, literally snapping off fastballs in the eighties flat-footed, is one of those things. As much as Rivera, Pujols, Greg Maddux, or Alex Rodriguez, Pudge is an outright freak. And even nearer the end than the beginning of his career, it’s always a privilege to watch him play.

As someone who more or less sides with Curt Schilling on the value of aura and mystique, it still gives me a chill to think of Ivan Rodriguez, one of the five or so best catchers of all time, taking the field in Yankee pinstripes. However this season turns out, between the two Rodriguezes, Rivera, and Derek Jeter, anyone lucky enough to have field seats at Yankee Stadium for the last two months of the season is going to see things they’ll be envied for 50 years from now.

On its face, yesterday’s trade, in which the Yankees grabbed the Hall of Fame catcher from the Detroit Tigers in exchange for Kyle Farnsworth, is surreal. Five-and-a-half games out in their division and six out in the wild card race, the Tigers are hardly so far gone that they need to start dumping players, let alone stars, let alone in exchange for third-rate setup men. (However well Farnsworth has been pitching lately, the fact that there’s a commercially printed shirt reading “Anyone But Farnsworth” more or less sums up his value.)

Detroit general manager Dave Dombrowski may be the best in the game, but handing a team with whom you’re at least notionally competing for a playoff spot a star player at a position of need is inexplicable. Yankees GM Brian Cashman, who admitted yesterday that he hadn’t even been looking for catching help, probably thought he was dealing with a prank caller when Dombrowski made the offer.

There should be no mistakes made about two points here: Even at 36, Rodriguez is still a star, and with Jorge Posada out for the year, this was a position of desperate need.

As to the first point, Rodriguez ranks sixth in the majors in OPS among catchers with at least 300 at bats. Defensively, he isn’t what he was a decade ago, when he routinely threw out more than half the base runners unfortunate enough to try stealing bases on him, but he’s still among the better receivers around. And whatever value you put on it, he was a field leader for two of the more improbable pennant winners of the decade, the world champion 2003 Florida Marlins and the 2006 Detroit Tigers. He’s one of the half-dozen top backstops in the sport.

The second point is equally important. Jose Molina is a perfectly fine reserve who’s caught 47% of would-be thieves this year, but even for a backup his .228 BA/.278 OBA/.303 SLG line is atrocious, and backup Chad Moeller is little better. Even by catching standards, the Yankees were losing more offense than they could afford in a tight race with these two behind the plate and Posada on the shelf.

Rodriguez started 73% of Detroit’s games this year. Given his production, if he starts an equal proportion of the Yankees’ remaining games and Molina starts the rest, they’ll probably be worth about 20 runs more than an average hitter between them. If Molina started 73% of the remaining games, and Moeller started the rest, as they presumably would have absent the trade, that would be worth about 15 runs fewer than average. Adding Rodriguez, then, could well be worth between three and four wins more than the status quo during the last two months of the season.

As should go without saying, that’s an enormous improvement, possibly enough to make the Yankees an outright favorite for a playoff spot. There’s little reason to think the loss of Farnsworth will do much to offset the gains Rodriguez represents. Partly that’s because he’s Kyle Farnsworth, inherently a man not to be trusted in the big spot, but there’s also the presence of Damaso Marte, Edwar Ramirez, Jose Veras, Brian Bruney, and David Robertson. That’s five relievers averaging more than a strikeout per inning; if manager Joe Girardi can’t piece together a decent setup corps with this kind of talent, the team is just hopeless.

Granting that it fell in Cashman’s lap, this deal is an outright masterstroke. It greatly increases the team’s odds of making the playoffs, it makes an asset out of what may have been their biggest weakness, and it gives every Yankees fan the chance to watch a true all-time great who still has a bit left in his gas tank. Rodriguez will drive you mad; he never has had much sense about what he likes to swing at, he falls in love with his own arm, and he’ll call the oddest pitches at times. Ignore it all and get the best seats you can some night when he’ll be catching. With any luck you’ll see something you won’t believe.

tmarchman@nysun.com