There haven’t been too many bright spots in Chicago Cubs baseball over the past few seasons. Apart from Darwin Barney’s spectacular defense at 2nd, the release of Carlos Marmol and some savvy trades that ultimately led to 1st baseman Anthony Rizzo, the bleacher bums haven’t had too much to cheer about since 2008. Starlin Castro was one of those bright spots.

Over the past 3 seasons the Cubs’ shortstop has managed to hit .298/.336/.425 with averages of 9 homers, 9 triples, and 32 doubles per year. That’s excellent production at the plate out of the shortstop position and all those hits netted Castro a pair of All-Star appearances. Castro’s defense at the position has never been up to snuff, but he made positive strides with both his glove and his arm a year ago, and at 23 the hope was that he still had room to improve.

That hasn’t exactly been the case though. Through the first half of the 2013 season Starlin Castro has seen a noticeable drop-off in every possible offensive and defensive category. He’s hitting more that 50 points below his career average, while simultaneously walking less and striking out more than ever before. His speed, which had been good enough to net 25 steals a year ago, has declined too and his defense is so bad it’s almost sad watching him stumble through routine grounders before failing to make the play. It was just two years ago that a then 21-year-old Castro led the National League in hits while posting a very solid 3.2 wins above replacement. Now he’s competing for the title of “Worst Player in Baseball” along with the likes of Ike Davis, Jeff Francouer, and Jeff Keppinger, so what gives?

Well, a big part of Castro’s problem is that he derives a large majority of his value through his batting average. He’s not much of a power hitter and he’s seemingly allergic to walks which means that Castro has to get base hits to have any value at the plate. In his first 3 seasons, Castro was able to do so regularly, posting a batting average on balls in play (BABIP) of .334 over the trio of seasons including a .346 BABIP during his stellar 2011 campaign. That numbers fallen back to earth this year (.287) and the results haven’t been pretty.

But that’s just the easy explanation. Any hitter is going to see a dip in positive results when the defense starts converting those seeing-eye singles into outs. What’s more concerning, and what lies somewhere beneath the surface is Starlin Castro’s complete inability to hit a fastball. According to Fangraphs’ Pitch F/X tool, the Cubs’ shortstop has been 9.2 runs below average against the fastball this season. Only Michael Brantley and Andrelton Simmons have been worse against the heater and that means opposing pitchers can attack, attack, attack with their best pitch once Castro steps into the box. This is a major problem for any ball player, particularly one with so many holes in the rest of his game.

And we haven’t even gotten into Starlin’s chronic inability to draw a walk either. He’s never been much of a patient hitter at the plate but the shortstop is taking things to the extreme this year. He’s is walking just 3.8% of the time while also striking out in nearly 18% of his plate and both of those percentages rank in the bottom 10 in baseball for position players. This was supposed to be something Castro and the entire Cubs organization was working on in Spring Training but here we are in July and Castro’s now on pace to walk less and post a worse on-base percentage than he did during his rookie season. That has to frustrate the Chicago coaching staff as much as Castro’s stagnant defense does.

To be blunt, Starlin Castro should not be a shortstop at the Major League level. He’s a no-good, terrible, awful defender and his issues are only magnified by the fact that he plays at the toughest spot on the infield. He’s well on his way to making the most errors in the National League for a 3rd consecutive season and it’s not as if he has fantastic range or turns a smooth double play either. Just check out where some of the metrics rank Castro. UZR (ultimate zone rating) says Castro has been worth -10.7 runs, which is 5 runs worse than the next closest shortstop in the Majors. Defensive runs saved credits Castro with a -8 this year, a number that bests only Erick Aybar and Jed Lowrie among MLB shortstops. And finally fielding percentage has him ranked 2nd to last among shorstops as well with a .970 percentage.

Just pay special attention to Castro’s footwork the next time you turn on a Cubs game. It’s all over the map. On one play, Castro will make a textbook pickup with his glove and quickly set his feet before making a strong throw for a putout. Then, almost as if he wants to drive Cubs’ fans insane, the very next play Castro will scoop up a grounder, shuffle his feet, pound the ball in his glove, then shuffle his feet some more before finally releasing a throw that’s too late or too off target to get the runner. Cubs’ manager Dale Sveum discussed some of these issues recently with Vinnie Duber of CSN Chicago saying:

“There’s a lot of things in his defense that need to get better. Today he was just working on his backhand, trying to get more stabilized, have a base when you throw the ball and not be so off-balance and understand the different things you have to have in your toolbox. Your backhand, there’s all different kinds of backhands according to the runner: slow, fast, medium grounders, backhand it, come in and backhand it. So it’s just some things you’ve got to get cleaned up.

“It’s having things in your toolbox and understanding that these are why things happen, this is why it’s happening. And he’s got to understand that, as well, so these things don’t keep happening. The body-control plays are still an issue that’s got to get better. The backhand and the body control are probably the two things he has trouble with the most.”

These footwork and body control issues are Castro’s biggest problem. If he can work on getting set quickly and efficiently the rest of his body will fall in line, which will lead to more accurate throws and more outs. It’s also worth wondering if Castro will ever learn the more subtle nuances of the position. Defense is part instinct and part repetition. Just watch Castro’s peer Andrelton Simmons when he’s in the field. Simmons’ entire body is fluid. He wastes no motion in getting to the baseball or in transferring it to his throwing hand. I’d be willing to bet that Simmons has looked this smooth at short since he was a kid and it’s probably safe to say this kind of fluidity in the field comes naturally to him. Castro just doesn’t have that. He has to think about every single move he makes when fielding and all that extra thinking ends in errors occasionally. A move to another position was always in the cards for Castro. The Cubs were just hoping it wouldn’t be this apparent so soon into his 8 year/$60 million dollar deal.

Big thanks to Fangraphs and Baseball-Reference for the statistical help!