A friend of mine recently introduced me to the Twitter feed of @FacebookCubs: "Actual comments found on the Cubs Facebook page. This account is run by a Cubs fan. I'm so sorry." Since it's Facebook, people are angry; since it's Facebook + the Cubs, people are extra-angry. What are they angry about now? Tony Campana, who was recently traded to the Arizona Diamondbacks.

There are a couple things to know about Tony Campana.

The first is that by some measures, he may be the worst hitter in baseball. Of all players with at least 190 plate appearances, Campana had the second-lowest isolated power behind punchless Wilson Valdez; he struck out 22.4 percent of the time, which is not horrific—it's a bit less than Alfonso Soriano—but is really, really not what you want in a player who can do extraordinary damage on the bases (more on that in a second). He only walked 5.7 percent of the time. Basically he's got Soriano's contact problems with Starlin Castro's lack of patience; it's a poor combination for someone you want on base by any means necessary. He's a poor man's Scott Podsednik. 

The second is that for a terrible hitter, he's surprisingly valuable. Campana is so fast, and such a good base stealer, that he's able to compensate for his inability to hit the ball. Matt Hunter of Beyond the Box Score found that Campana is historic in that sense: "Tony Campana is the only player [in 90+ years] to strike out more than 20% of the time with an ISO under .040 who still provided positive value to his team according to fWAR. Yes, this means very little, but I find it pretty fascinating."

Translation: of players that strike out as much as Campana, and who have as little power as Campana, he's the only one that wasn't total dead weight on the roster. If you want to know how bad Campana would be without his speed, the best comparison is… his teammate Marlon Byrd last year, whom the Cubs couldn't get rid of fast enough.

Basically the only thing that makes Campana better than your typical AAA filler is his base stealing. Which he's better at than anyone else:

If you extend the leaderboard back to 2011, you’ll actually see that Campana rates #2 in Major League Baseball in runs added through base stealing, behind only Coco Crisp, a player with 750 more plate appearances. Campana has created more runs through base stealing the last two years than Michael Bourn, despite the fact that Bourn has almost 1,100 more plate appearances and is one of the game’s best baserunners.

Does it mean very little that Campana has a historic, extremely limited skill set? Perhaps not; for a team expecting to be in the playoffs, Campana could be a good asset, giving the Diamondbacks the best baserunner in the game in the highest of high-leverage situations. But the Cubs are unlikely to make the playoffs, or come close. What they're trying to do is rebuild their farm system, and they got two pitchers from the Diamondbacks… Erick Leal and Jesus Castillo, two very, very young pitchers, both 17-year-olds. 

Photograph: Chicago Tribune