Cubs by the Numbers: Defense as Expressed by UZR

With the 2014 MLB Gold Glove Award finalists being announced, I wondered to myself when a Cub not named Darwin Barney was going to be on the list again. But then calmer heads prevailed and I remembered that this list is very subjective and not truly based on defensive metrics, so I instead decided to focus on reviewing the Cubs’ defense for 2014.

There are several metrics that measure defensive ability. UZR (ultimate zone rating) is kind of a catch-all for defensive stat lovers, but there are other categories that are interesting as well: ARM (Outfield Arm Runs), DPR (Double Play Runs), RngR (Range Runs), and ErrR (Error Runs). These metrics all get added together to give a total UZR.

• ARM=Runs above average that an OF saves with his arm.
• DPR=Runs above average that an IF is at turning the double-play
• RngR=Measures how many balls on average a fielder gets to
• ErrR=Measures how many more or less errors a fielder commits compared to others that play the same position.

Here is Fangraphs’ break down of how that UZR number breaks down:

With that frame of reference in place, now is a good time to break down some of the best and worst defensive performers in terms of UZR.  Keep in mind that this is a counting statistic (like hits, runs, RBI, etc), so playing time does impact the total number. Also, UZR is not used to measure catchers. They have their own categories, which I covered in some detail on my article about Welington Castillo.

Anthony Rizzo was the Cubs’ leader in UZR with a score of 7, right between above average and great, which I feel is a pretty accurate description of his defense. His UZR was developed by a 0.5 DPR, 6.4 RngR and 0.1 ErrR. To sum up his total, he was aided by using his range to get to several more balls than the average first baseman.

Next up on the list of Cubs that are still with the team is Junior Lake with a UZR of 5.3, which was assisted by an impressive 7.7 RngR but hampered greatly by his -1.3 ARM and -1.1 ErrR ratings. He can get to more balls than average, but once he gets there it is no guarantee that he will do what he is supposed to do with it.

Perhaps the most interesting entry is Arismendy Alcantara and his play at 2nd base.  Granted, he only played a little over 200 innings there, but he provided a slightly above-average performance of a 3.4 UZR.

While at the keystone position, Alcantara had a decent RngR score of 3.1 with a DPR of -0.1 and an ErrR of 0.3. So he can get to a fair amount of balls, was not great, but certainly passable, at turning the double-play and was above-average when it came to not making errors.  For comparison’s sake, he had a -2.4 UZR in over 400 innings as a CF.

Starlin Castro’s defense appears to have improved over the years as his focus has matured, but his -3.8 UZR would beg to differ with that statement. In fact, this past year was the 2nd-lowest UZR of his career behind a -7.5 in 2011. Castro’s 2014 total was dragged down by a poor range of -6.2, but he was pretty adept at turning the double-play, with a 2.1 DPR, and he did make fewer errors than average with a 0.3 ErrR.

Other notable Cubs’ UZR scores:

• Javier Baez at 2nd (210 innings, small sample size)= -3.2 UZR
  • Slightly above average at turning the DP with a 0.7 DPR
• Luis Valbuena at 3rd (971 innings)= -3.7 UZR
  • Bad at RngR: -4.2 and turning DP with -0.7 DPR
• Chris Coghlan at LF (812 innings)= 0 UZR
  • Above-average ARM: 1.7, slightly below average in the other two
• Jorge Soler RF (205 innings-Small sample size)= -0.5 UZR

Nothing overly surprising from these numbers, except for Castro, who I really had thought was much improved at short this past season. I don’t think Baez would be much better in the long run though because what he would undoubtedly make for in range, he would also hurt with more errors than average.

After looking at these numbers, I think the Cubs should not hesitatate in moving Castro off of short for Addison Russell when the time is right. I get the argument that Castro is an All-Star shortstop and that the offense he can provide there is great, but defensively you can definitely see that he is below average there.

With the current roster, if anyone is eventually going to challenge for a Gold Glove (which, again, isn’t the be-all-end-all for awards), I would put money on Rizzo being the Cub most likely to break through and get the recognition.