Last year, the Arizona Diamondbacks were baseball’s biggest surprise, winning 94 games and the NL West title just a year after finishing 65-97. The team’s turnaround was driven by strong performances across the roster, but among the key factors in their success was the excellent defense delivered by their trio of outfielders. Chris Young (+14.1), Gerardo Parra (+9.6), and Justin Upton (+7.7) all posted UZRs that ranked among the best in the league at their positions, and the Diamondbacks posted the best team outfield UZR (+31.1) in the National League. With the help of their strong gloves, the team was able to post an ERA (3.80) that was 22 points lower than their FIP (4.02), the fifth largest positive differential in the game.
Well, today, the team decided to change course, signing Jason Kubel to a two year, $15 million contract that will see him take over as the team’s left fielder. By acquiring Kubel, the D’Backs have essentially chosen to displace the incumbent Parra, and in looking at the two players, it’s not actually clear that the team is going to get any better.
Kubel’s addition signifies that the Diamondbacks wanted a bit more power from the left side to balance out the right-handedness brought by Upton, Young, Paul Goldschmidt, and Aaron Hill. While Miguel Montero and a potentially healthy Stephen Drew offered some power from the left side, the middle of the team’s batting order still skewed towards RHBs, and Kubel will give the team more thump at the plate than Parra would have. However, if the team thinks they’re getting a monstrous offensive upgrade in making the switch, they’re likely overestimating the difference between them.
While Kubel put himself on the map with a good 2009 season, he’s generally been only slightly better than an average hitter for most of his career. His career line of .271/.335/.459 is good for a 109 wRC+, almost a dead ringer for the 110 mark he put up last year. While he has some power, he’s not exactly a prototypical cleanup hitter, and he’s just about average in terms of drawing walks and avoiding strikeouts. At the plate, he’s okay at everything, and the overall package adds up to a decent-but-not-great offensive player.
How much better is he than Parra at the plate? Here are their career numbers side by side.
|Jason Kubel||Twins||2846||.271||.335||.459||8.8 %||18.7 %||.188||.303||109|
|Gerardo Parra||D’backs||1377||.282||.331||.403||6.6 %||17.9 %||.120||.338||88|
The walk and strikeout rates are similar, though it should be noted that Parra has drawn 23 intentional walks while hitting in front of the pitcher, so some of his perceived patience at the plate may be more of a factor of NL batting orders. Kubel has a big edge in power, though Parra’s speed has let him make up some of that difference with a higher BABIP. Overall, the offensive difference between the two based on their career numbers is about 15 runs over 600 plate appearances.
However, we probably shouldn’t just be content to use their career numbers. Kubel is five years older than Parra and is three years removed from his best season, while Parra showed signs of legitimate improvement at age 24 last year. If we give more weight to their most recent seasons, Parra’s wRC+ comes up to something closer to 95, cutting the difference between them to something closer to 10 runs over the course of a full season. It’s an offensive upgrade, but not a huge one.
And then we get to the parts of the game besides standing in the batter’s box, where Parra just destroys Kubel in value. This shows up most significantly on defense, where Kubel has essentially proven to be so bad that he should probably have been moved to permanent DH by now. In just over 3,000 innings in the outfield, he has a career UZR of -41.8, or about -17 runs per 150 games played. Even if you think UZR overstates the case against Kubel’s defensive prowess, he’s clearly below average at best and outright bad at worst. Even a strong regression on UZR will still leave you with an expectation of Kubel costing the D’Backs about 10 runs compared to an average defender if they run him out there as their regular left fielder.
And remember, Parra is not likely an average defensive left fielder. He has the skillset of a guy traditionally used in center field, and indeed, he’s racked up 360 innings of time in CF even with the D’Backs having a quality defender in Young already on the roster. In his nearly 2,000 innings of Major League experience in the outfield, Parra’s racked up a UZR of +22.5, or just about +10 runs per 150 games played. Given his player type, we should expect him to be better than the average left fielder, and defensive metrics suggest that this is exactly the case. Again, you can regress UZR if you don’t trust it’s conclusions, but you’re still going to come out with Parra being something like a +5 defender over a full season.
A +5 expectation for Parra and a -10 for Kubel would give us a gap of 15 runs defensively between the two, or about the same as the offensive difference between them strictly based on career numbers, ignoring Parra’s strong 2011 season and how their ages should inform our future projections. Once you add in baserunning (Kubel is lousy at this too) and durability, it’s really hard to make the case that Kubel is a better player than Parra. He provides a different set of strengths, but his weaknesses more than offset what he’ll bring to the table, and swapping out Parra for Kubel is likely to be a net negative for the Diamondbacks.
Now, Arizona might argue that it’s not either/or, and that they can have both on the roster with Parra moving to the fourth outfielder role, but that doesn’t really seem to be a very good use of resources. Both Kubel and Parra are left-handed bats, so they wouldn’t be able to platoon them and minimize Kubel’s struggles against southpaws. Meanwhile, Parra’s not going to take playing time from Upton in right field, and using him in center field in lieu of Young would only serve to make the defense even worse without really upgrading the offense in any meaningful way.
With Kubel as the left fielder, Arizona’s fourth OF should be a right-hander who can give Kubel days off against LHPs and substitue in for him defensively late in games, and Parra only fits half that bill. If they’re not sold on him as a regular, they’re better off trading him to someone who is, and finding another player to get the 200-250 PA they’ve left over for him after signing Kubel to take his job.
Overall, this is just a weird signing. The Diamondbacks didn’t really improve themselves, displaced a decent young player, and gave up about 10-15% of their payroll to make this lateral move. They could potentially rescue this deal by moving Kubel to first base (where he could platoon with Goldschmidt), but it doesn’t sound like that’s in the plan.
In their chase for left-handed power, the Diamondbacks likely just wasted a roster spot and $15 million over the next two years. For a team with a limited budget, this isn’t the kind of move they should have been making.
Dave is the Managing Editor of FanGraphs.