Defense has been a hot topic this off-season. The team has talked about improving there. They let Matt Holliday and Brandon Moss go, replacing them with Dexter Fowler. It’s also been a reason to not acquire players. With only one major move on the position player side, people are wondering: is that enough to turn around the defense? Well, it’s a start. The other is sticking to doing things that the team has talked about doing.
We’re going to talk about advanced defensive metrics. One of those, is Ulimate Zone Rating (UZR). Here is a page that explains how it works. UZR grades a player by how well he’s defended his positon relative to others at that positon. They do so in terms of runs above or below average. Of course, some positions are harder to play than others. In order to make an apples to apples comparison, Fangraphs uses a positional adjustment to put all positions on an equal footing, for the purpose of calculating a player’s overall defensive value relative to the league. There’s also Defensive Runs Saved (DRS). DRS is calculated in a similar way to UZR, but was developed by different people and uses different inputs. We’ll also look at DRS to get more information, though UZR will get most the attention, because it’s tied to overall defensive value on Fangraphs’ leaderboards, making it easier to use.
You might have heard that advanced defensive metrics like UZR and DRS are unreliable in short sample sizes. Specifically, the rule of thumb is to use three years of numbers to get a good idea. That is because most plays are routine plays, either almost always a hit or an out. In between plays are where fielders have to differentiate themselves in terms of value. A player could boot a few of those, leading to a much worse defensive rating then expected, or pull off all of them and look like a perfect defender.
With that out of the way, you might have already guessed what we’re going to do here. We’ll compare - by position - how the Cardinals’ defense did in 2016 to how they could do in 2017, depending on who gets playing time where. We’ll just skip the catchers’ position. Last year Molina caught a ridiculous amount of innings, and he’s expected to do so again this year. Besides, there’s a lot more to catcher defense than what these public stats cover. First stop is first base, where the team says they plan to start Matt Carpenter full time. Here’s how the position graded out last year:
First base has a positional adjustment of -12.5 runs, which essentially means even the very best first basemen are below average defenders overall. UZR/150 is a players’ UZR score per 150 games worth of innings at the position. “RngR” stands for runs above or below average in terms of range. “ErrR” are runs above or below average in terms of errors.
Matt Adams was an above-average first baseman this year, and has been overall in his career. Brandon Moss, however, received a significant amount of time there last year, scoring very poorly. In nearly two years worth of innings there, Moss has been 16 runs below average according to UZR (before considering the positional adjustment).
Matt Adams would be fine at first, but Matt Carpenter looks to be an improvement. For his career, Carpenter’s position adjusted value is -4.2 runs per full season. That’s as a generally below average second and third baseman. As a whole, below average third basemen should make for above average first basemen. At first base his value might slip a bit, but he figures to still be a real improvement over last years’ score of -12.3.
First base improvement: +5 runs
Next up is second base:
Second base did fine defensively in 2016. As a whole, the position did 4 runs better than average relative to other second basemen. If the Cardinals really do stick to Kolten Wong at second, with Gyorko taking time aganst lefties, they should expect similar results. Wong has a career 3.9 UZR/150, and DRS likes him more than twice as much as UZR does. In two seasons worth of data, Gyorko has a 1.2 UZR/150, above average but not on the same tier as Wong. Second base should be a wash. On to third base:
Peralta spent a plurality of the innings at third last year, and that’s who the Cardinals expect to man the spot in 2017. Since he did the worst on a rate basis, you might be inclined to believe the position won’t improve. But this is where short sample sizes can confuse people. As you see, UZR tracked 95 plays. According to Inside Edge fielding, Peralta only had 30 plays at third which were neither impossible (0% chance of making play) or routine (90-100% chance of making play). We wouldn’t want to judge a hitter much based on 30 plate appearances, so we wouldn’t want to judge a fielder too strongly on 30 plays.
A better way to judge Peralta is on his defensive performance at every position over the last three years. With everything adjusted based on position, Peralta has been 3 runs above the average player per 150 games. Perhaps he’s declined some over that time, but he didn’t go from a strong defender at short to a weak defender at third over night. Third base has a +2.5 run positional adjustment, so Peralta should be capable of playing at least close to an average third base.
Third Base improvement: +6 runs
Besides catcher, shortstop has the highest positional adjustment, at +7.5 runs above average. Diaz is the presumed starter, and by UZR/150 was -11.4 runs worse than average, meaning he was a below average defender relative to the league, despite getting credit for playing one of the toughest positions. However, I don’t think I’m alone in saying Diaz improved as the season went on last year. The projections agree, and see him as a slightly above average defender overall. Let’s assume he’s a neutral defender in 2017, meaning he’s -7.5 runs below average among shortstops.
Shortstop improvement: +8 runs
Let’s shift our attention to the outfield now:
Here’s center-field. Grichuk was slightly below-average. Pham was incredibly bad, even when considering the short sample size. Hazelbaker wasn’t great either. Much has been made of Dexter Fowler changing his positioning the last two years. In those two years, Fowler scored a -0.7 UZR/150. If you expect that going forward, center-field defense has been moderately improved.
Center-field improvement: +6 runs
Center is moderately improved by adding Fowler, but the big improvement comes as an indirect result of improving center:
Due largely to Matt Holliday’s presence, left field performed horribly last year. That will be upgraded by Randal Grichuk moving over from center. For his career, his adjusted defensive value is 8.1 runs above average. That’s with about a season and a half of innings, so his defensive value per 150 games is 5.7 runs. That makes for quite the upgrade over last years’ left-fielders.
Left-field improvement: +16 runs
Right-field should be relatively unchanged, so we’ll skip that. Add up all of these improvements, and we get a 41 run improvement! Last year, the Cardinals placed 24th in defensive value, with 32.8 runs below average. It seems like just adding Fowler and making re-arrangements the team already planned to make, plus expecting some bounce-back, should make them an above-average team defensively. How big of a deal is 41 runs? It translates to about 4 wins. It’s not as simple as just adding 4 wins to last year’s record (which would have meant the team would have hosted the Wild-Card game rather than missing it entirely), but doing so can create a pretty clear picture of the difference that makes for a play-off contending team.
Still, let’s not get ahead of ourselves. Matheny has never prioritized defense. We don’t know if Wong will actually finally get everyday playing time, nor do we know that Carpenter will stay at first. Matheny could shift Carpenter back to third or second (or outfield!) in order to get Matt Adams’ bat in the lineup. The difference between Matt Adams and Kolten Wong on offense could easily be as much as a win over a full season.
However, the offensive upgrade is minor, and we see that it would have a much larger affect on the team’s defense. It can be achieved though. It just takes sticking to the team’s plans. If you grew tired of the Cardinals’ defense last year, there is a solution. We’ll see if they stick to it.