Walt Weiss has repeatedly professed that he wants his pitchers to supply ground balls. One reason for that is because fly balls in Coors Field are liable to have a bad outcome for the pitcher. Another is that the Rockies have an elite infield defense where ground balls are converted into outs at a fantastic rate.
As Troy Renck points out in the linked article above, the four projected regulars in the infield (Justin Morneau, DJ LeMahieu, Troy Tulowitzki, and Nolan Arenado) all ranked in the top four in MLB at their position in Baseball-Reference's Range Factor, with LeMahieu and Arenado being the league's best. There aren't going to be a whole lot of ground balls getting through that infield ... and if the Rockies embrace the defensive shift more in 2014, even fewer ground balls than ever could turn into hits.
This is perhaps an under-reported story going into 2014 -- that Colorado's pitchers will have a larger margin of error with a rangy infield playing behind them. Arenado (the 2013 Gold Glove winner at third base as a rookie) and Tulowitzki (Gold Gloves in 2010 and 2011) are the headliners, making spectacular plays left and right. The best thing about those two is that the Rockies are actually getting plus offense from those positions too (I'm a believer Nolan, 2014 All-Star!). No worries there at all.
Morneau and LeMahieu are bigger question marks in terms of overall assets to the Rockies. Morneau is a question because of his age (he'll play most of this year at 33), injury history (hasn't been the same since some concussions a few years back), and the fact that he's been terrible against lefties (career .297 OBP against, .247 OBP in 2013). Meanwhile, LeMahieu just hasn't shown that he has the potential to be a good offensive player (career 77 OPS+, .314 OBP, and .371 SLG).
In LeMahieu's case, his glove will be enough to make him a league average player (given a full season of plate appearances) if he continues to hit at his 2013 rate, which would honestly be just fine from Colorado's sixth or seventh best regular. Still, Josh Rutledge lurks as a competitor to DJ given his superior offensive tool set. If Rutledge wins the job at any point during the season, the Rockies will lose some range at second base but will (presumably) gain some offensive utility in return.
With Morneau, I'm not nearly as concerned about him offensively so long as the Rockies minimize those plate appearances against lefties -- but we all know that those PAs will occur more often than we'd like. Fortunately, the Rockies have Morneau's old Twins buddy Michael Cuddyer to play first base when a lefty is on the hill. When this occurs, the Rockies will see a small hit to their infield defense ... but a large gain in outfield defense.
While Cuddyer is one of the strongest components of Colorado's lineup, he is by far the weakest link in Colorado's defense this year. As a first baseman, he should be fine, though his ability to scoop low throws like Todd Helton has come into question. It's in right field that his lackluster range combined with the huge tracts of land in Coors Field's outfield hurts Colorado the most. Knowing this, the Rockies set about acquiring some good defensive outfielders this off-season.
Drew Stubbs was the headliner, a speedy player who the Rockies were able to acquire from the Indians for reliever Josh Outman. Scouts love the way Stubbs plays the outfield, but defensive metrics (yes, the same ones that hate Rockies outfielders) aren't as convinced, rating his range as below average despite that excellent speed. To boot, Stubbs was last an effective offensive player in 2010 ... and in that year his batting line was .255/.329/.444. I think that the move to Coors will help Stubbs on offense, but I'm not convinced he's the right choice in center field.
Brandon Barnes, acquired in the Dexter Fowler trade, is a defender that both scouts and metrics love. His range factor was second in MLB last year among all center fielders (and third among all outfielders) and his arm also rates above average (he turned the most double plays in MLB last year as a center fielder). Unfortunately, while Barnes has been passable at the plate against lefties (.280/.335/.401 BA/OBP/SLG line), he's been abysmal against right-handed pitchers (.207/.251/.290), making it highly unlikely that he'll ever be more than a reserve outfielder at the big league level.
The other two contenders in the center field derby, Charlie Blackmon and Corey Dickerson, have fewer problems with offensive projection. Both players are left-handed but Blackmon's numbers are actually better against lefties. Dickerson has struggled against lefties in a small sample (.194/.275/.306 in 40 PAs), but has the potential to be an above average player at the MLB level. Meanwhile, Blackmon has already put up an above average offensive season (.309/.336/.467, 107 OPS+ in 258 PAs). Dickerson's ceiling is higher given his power, but both are at least passable MLB bench players on offense alone. It's on defense where those questions tend to arise with both players.
Dickerson's arm is dreadful, stemming from a labrum injury in college, and he'd never played center field as a professional until the MLB level. Every routine fly ball seemed to be an adventure with Dickerson out there, which is why I'm more than a little leery of letting him patrol that real estate on a regular basis. Blackmon has more of a pedigree in center, but he hasn't exactly wowed me (or the metrics) in that capacity either. Both players profile more as a corner outfielder than they do in center.
All of this is why I really wanted Carlos Gonzalez (a better defensive player than all but possibly Barnes) to slide to center this year, with Dickerson or Blackmon filling in at left field, but that's not the case. As it stands, the Rockies will probably need to choose between competent offense or competent defense at center field.
Which should they choose?