An early look at the Cardinals' defense

The Cardinals have gotten off to a great start so far this season, highlighted by their good run scoring and great run prevention. As a team, the Cardinals have the best ERA in baseball (2.53), are third in FIP (3.16) and pitching fWAR (4.6), and eighth in xFIP (3.60). Based on their team FIP and xFIP, it may not be reasonable to expect the Cardinals to continue to have the best team ERA in baseball. (The losses of Adam Wainwright and Jordan Walden won't help either.) With that being said, the Cardinals appear to have a very good defense, which is one of they reasons why they have outperformed their FIP so far this year.

Typically, we see very little discussion of defensive metrics early in the season, mainly because they take a very long time to stabilize, as Russell Carleton of Baseball Prospectus points out. In other words, it takes a very long time for us to get a good understanding of a player's true talent level on defense. Nevertheless, it can be interesting to look at some of these early season defensive numbers just to see if our perceptions about a player's defensive performance are true or not.

First, here are the team's overall defensive numbers, and where they rank among major league teams.

By most metrics, the Cardinals have the second best defense in baseball, trailing the Kansas City Royals by a very wide margin. (Fun fact: the Royals Def, DRS, and UZR values are around twice those of the Cardinals.) Def, UZR, and DRS are counting stats that use different methods to estimate the number of runs saved (or lost) by a player or team, and so far, the Cardinals have succeeded in saving anywhere from 11 and 17 runs with their defense (as compared to an average defensive team).

UZR/150 is a rate statistic scaled to the average number of defensive chances for a season, and according to this metric, the Cardinals have saved around 17 runs per 150 defensive chances. To put this in context, the highest UZR/150 in baseball last year was the Orioles at 10.9. The Cardinals, who had one of the better defenses in baseball last year, had a team UZR/150 of 3.0 last year. Needless to say, the Cardinals defense has been ridiculously good so far this year.

So which players are responsible for this amazing defensive start?

Catchers

As you can see, the defensive metrics available for catchers are rather limited (at least at Fangraphs). There may be reason to worry about Yadier Molina's pitch framing, at least if you believe Rob Arthur over at FiveThirtyEight, and his other defensive numbers appear to be down as well, at least relative to his very high standards. Since 2005, Molina has posted a Def between 14.3 and 21.9 every season, including last year, when he missed significant time with a thumb injury. He is off his usual pace so far this year, despite being healthy and playing in 23 of the team's 28 games going into Friday night. Tony Cruz has actually had a higher Def per innings caught, but the sample sizes here are too small to draw any major conclusions.

Personally, I'm hopeful that Molina will recover and still be a very good defensive catcher. It's foolish to put much stock into one month's worth of defensive metrics, especially when we're looking at someone with a track record like Molina's. So far this season, the Cardinals' catchers haven't been a huge part of their success on defense, but they've still been above average. Given the team's overall defensive numbers, it seems crazy to think that there are areas where the team could get noticeably better defensively, but based on what we've seen Yadier Molina do before, there is room for defensive improvement at the catching position.

Infielders

The Cardinals' infield defense has been pretty good so far this year, as three of the four starters appear to be solidly above average. Peralta appears to be continuing his excellent defense from last year, and Wong and Carpenter have been average or slightly better so far this year. Pete Kozma has played so little that his numbers mean next to nothing. For example, in seven innings at third base, he has a 52.6 UZR/150, but in 11 1/3 innings at shortstop, he has a -49.4 UZR/150. Over his career, Kozma has been an above average shortstop, and we will need to see a much bigger sample size before we can conclude otherwise.

Matt Adams, who had a decent season on defense last year, is off to a bit of a slow start at first base this year. Luckily, it doesn't appear that his defense has cost the team many runs so far, and Adams has plenty of time to get his numbers back into plus territory, where they were last season. Meanwhile, Mark Reynolds has done a fine job filling in for Adams at first, as he is (somewhat oddly) tied for the team lead with four defensive runs saved (which doesn't include his limited work in the outfield). Reynolds was never seen as much of a fielder until he had a good year last year, and he appears to be continuing that trend.

Outfielders

The Cardinals' outfield defense (outside of Hatt Holliday) has been nothing short of incredible so far this season. Jon Jay currently leads not just all center fielders but all of baseball in UZR/150. I bring this up because I want to start another Jay vs. Bourjos war at VEB it illustrates how much defensive numbers can fluctuate early in the season. I'm not saying that Jay hasn't had a great month in the field so far this year, but this is the same player who had a solidly below average season in center field just two years ago. All in all, Jay is probably an average or slightly above average center fielder, and he's definitely playing some of the best defense of his career right now.

Jason Heyward is playing his usual brand of excellent defense in right field. If anything, he could be slightly better, as he has consistently put up a UZR/150 of at least 20 each of the last three years. Peter Bourjos is also doing very well in center field, and given his good hitting so far this year, he will likely receive more playing time, as Joe wrote about yesterday. To his credit, Mike Matheny hasn't been swayed by Jon Jay's great defensive month; every time Bourjos and Jay are playing at the same time, Bourjos has been in center field, and it should stay that way until Jay proves otherwise over a long period of time.

Randal Grichuk and Mark Reynolds have both played very well in the outfield so far this year, albeit in a very small number of innings. While neither of these players is expected to be a gold glove outfielder anytime soon, there are no indications that they will hurt the team with their defense. In fact, the only Cardinals player that we can safely say will be a negative in the field is Matt Holliday. While Holliday actually had one of his best defensive seasons last year, he was no better than average, and he has consistently been a below average fielder throughout his career. As he ages, Holliday will likely remain a liability in the field, but given his level of offense, the Cardinals are probably perfectly okay with this arrangement.

While the Cardinals defense has gotten off to a great start so far, they are probably due for some regression. No player that we know of has saved 57 runs in a season, and Jon Jay will not be the first player to do so. With that being said, we shouldn't be extremely surprised by their overall team results so far. The Cardinals were already one of the best defensive teams in baseball last year, and they made a huge improvement in right field with the addition of Jason Heyward. With one move, they went from being slightly below average defensively in right field to having the best defensive right fielder in baseball.

What's amazing is that there is still room for improvement. Yadier Molina and Jason Heyward, who are still having good years defensively, have shown that they can be even better. If Peter Bourjos keeps hitting like he has been, he will get more playing time, which should help the team in center field defensively.

If the Cardinals can come close to maintaining what they have done on defense so far this year, this will continue to be a very fun team to watch.