I recognize that the conceit of their post seems ridiculous. After all, Jose Iglesias is an immensely talented defender. We’re frequently dazzled by his superlative play to the point at which Matt Mowery invented a silly acronym to tweet each time he makes a big play:

So why am I wondering if Iglesias is having a meh year with the glove? Or let’s say, an average year. According to Defensive Runs Saved and Ultimate Zone Rating, two of the leading defensive statistics in baseball, he’s been worth -2 DRS and 1.5 UZR relative to other shortstops. In other words, he has been about average relative to his peers. Now certainly an average shortstop is more valuable than an average left fielder, so when you factor in the positional adjustment, Iglesias’ defense has been worth 5-7 runs above the average defensive player. That’s a fine number, but it’s not an exciting one considering the tools we see him flash.

There are three possible explanations.

1. The stats are wrong for some reason
2. Iglesias is awesome, but it having a bad year
3. Iglesias isn’t awesome and this is a normal year.

Let’s consider them in turn. The first is the explanation most people will latch onto. You have watched Iglesias enough to know that he makes very difficult plays. That is a fact about which we can all agree. He makes great running catches, throws on the run, etc. We have seen him display this ability enough times to recognize it as a skill. It’s there, so the fact that the stats are saying otherwise is likely evidence that the stats are incorrect.

This is a plausible hypothesis. Defensive stats like these are based on imperfect data. Fielders are judged based on their performance relating to similar batted balls elsewhere in the league, both as a matter of making plays and how valuable it is to make each kind of play. But the data is based on a number of things logged by humans, who are imperfect, and an algorithm that was programmed by humans. DRS and UZR aren’t like on-base percentage where we can say for 100% certain than a player reached base. OBP’s flaws are a product of how much credit the player should get for each time on base, but no one disputes and there is no argument about whether it happened or not.

For defensive stats, this isn’t always true. Depending on how you design your program, a ball one system thinks is a 60/40 play (i.e. 60% of the time a SS makes that play) might get called a 70/30 play by another. The system can definitely tell if a play was made or not made, but it is estimating the difficulty of the play and the value of making the play. Right now, both systems think Iglesias’ value has been about average.

It’s only been 922 innings of play this year. We’ll get to this later, but most defensive numbers are swung by a small number of plays each year, so if the system has a certain number of errors in measurement, 900 innings might not be enough for the flaws of the methodology to get washed out.

The second option is that Iglesias is very good, but he is just having a bad season. This one is the most likely explanation to me on its face, but probably the one people are least likely to accept to begin. We have this idea that defense and base running are not variable skills. That is wrong. If a batter has a 120 wRC+ one year and then hits 98 wRC+ the next, no one jumps up and down blaming the stat. Maybe the player had bad BABIP luck, maybe they didn’t hit for as much power, or maybe they struck out too much. It happens. Performance year to year isn’t consistent. The same is true for defense.

So it’s possible that Iglesias is generally as talented as we think, but he’s just had some bad games or plays. Think of it like a starting pitcher. Remember 2013 Verlander? You blocked it out? Allow me to remind you. He was awesome in April and September and not so awesome in between. No one argued that the stats were to blame for this varied season, he simply pitched better at one point in the year than others. Defense can work the same way. Maybe you’re nursing an injury, or maybe you’re just fumbling your footwork. It happens. In 2013 we saw Verlander hit 98 that night he got rocked in Texas. We all knew he still had the raw skills, but he didn’t execute. The same could be true for Iggy. The range, arm, and hands are clearly still part of him, but maybe he has failed to use them as effectively as possible over this 900 inning sample.

The final theory is also possible. Maybe he just isn’t as good as we think. I think this could be true in a roundabout way. I’m not arguing he doesn’t have a good arm, but way too many people think defense = skill and it doesn’t. Defense is about a player’s ability to turn batted balls into outs. If you have a cannon for an arm, but you can’t get the ball out of your glove quickly enough, the arm value diminishes. Maybe you have a great arm, but perhaps you make good throws inconsistently. An outfielder might be super fast and have the ability to read the ball well, but maybe their first step just isn’t up to par.

You have to be able to consistently execute in order to be a good defender. Maybe that isn’t true for Iglesias. Perhaps he has great tools, but sometimes can’t make them work in his favor. I’m not saying this is likely, but it would fit with the facts that he looks amazing but his numbers haven’t been great.

*****

So let’s jump back to the facts. In his career, Iglesias has about a season and a quarter of innings at shortstop. He has 5 career DRS and 10.9 career UZR. He’s somewhere between +3 and +8, let’s say over a full season so far. A great SS would be 10-15, with generational talents in the 15-20 range per year. It could definitely be sample size and a flaw in the system. The best way to test this is to look at other evaluations and other indicators. The first thing we have to establish is if, in fact, Iglesias isn’t having a productive defensive year.

My favorite quick test for infield defense is BABIP on ground balls to your general area. This is essentially a very rudimentary metric. I carved up the field and looked at ground balls. Granted, Iglesias hasn’t played every inning at SS and there are positioning considerations and such, but let’s just use it as an independent test. If we give him 55% of the left side (angle-wise), the Tigers have allowed a .299 BABIP, which ranks 30th (.251 is average). If we give him 65% of the left side, it’s .323, which ranks 30th (.259 is average).

Now this is just ground balls and is not at all sophisticated, but it generally lines with the idea that Iglesias isn’t converting a ton of batted balls into outs. Of course there is a Castellanos factor, so let’s be really nice to Iggy and only give him 45% of the field, which no 3B would ever cover. BABIP of .233, which is only 9th worst! Still not the mark of a good shortstop.

We also have access to Revised Zone Rating, which measures the percentage of balls in his zone (plays that get made more than 50% of the time) that he has turned into outs. This year it’s 77.5% which ranks 18th among qualified shortstops (25 in total). Per inning, no one has made fewer out of zone plays than Iglesias too, and only Wilmer Flores has the same number. Another point against him.

Let’s move to Inside Edge, which is a totally different company than bins plays based on how difficult they are. No run values, just difficulty and if the play was made. He’s 259 for 264 on the easiest set of plays, which ranks 9th. He’s 18 for 25 on the 60-90% play range, which ranks 14th. He’s 8 for 11 on the 40-60% plays, ranking 5th. He’s 3 for 13 on the 10-40% plays, ranking 14th. He’s 1 for 11 on the 1-10% plays, ranking 3rd.

So the Inside Edge data generally backs up what we’ve seen. Iglesias has been average or a touch better by their methodology. He’s made 89% of the non-impossible plays (plays literally no SS could make) this year. That’s a fine number, but not a great one. Keep in mind this doesn’t cover double plays and tags and such.

So the data does seem pretty clear. Iglesias is making an unimpressive number of plays. No one is contesting he has made some very difficult plays, but it does seem like the raw totals are lacking. He’s not bad, but he’s not preventing a large number of total runs.

So what’s the explanation? What does this all mean? I think the “stats are wrong” argument is weak. We’ve sliced and diced this with a variety of numbers and the same thing keeps coming up. I mean, he’s even 16th in fielding percentage, as useless as that stat may be. There isn’t a good case to be made that the numbers are somehow tricking you.

So either he’s a good player having a bad year, or he’s not as good as we think. Maybe we should blend the two categories. Here’s how I see it. Iglesias is obviously extremely talented. But he seems to fail to execute a non-trivial amount of the time. Sometimes that means he boots a play, sometimes he gets cute and makes a bad throw, sometimes that means he doesn’t go all out after a ball up the middle. Presumably, this is a correctable issue. We’ve seen him flash these tools plenty, so it’s about some type of extra work. It might be mental focus and it might be extra reps to get out of certain bad habits.

Very few players, if any, can get to some of the balls he gets to while making the kinds of throws he makes. By talent, he’s probably one of the best three shortstops in the game. But by results, he’s in the 10-15 range this year. Maybe he’s just having a bad year, but it’s not like he’s been immune to this in the past. Defense isn’t just about being able to make the play, you have to actually make it. This is not a trivial distinction.

Almost every pitcher can hit the corner with a fastball, but the great pitchers are the ones who hit the corner the most. The same is true for defense. And it’s especially true because the difference between good and great defenders comes down to about two plays per week. So much of defense is routine that separating yourself from the pack means you can’t make very many mistakes and have to convert the plays that make the biggest difference.

I’m confident that Iglesias is capable of being an elite shortstop, but I also think it does seem like he gives away a number of runs he saves by botching relatively easy plays. Few make the tough plays as well, but many execute the slightly difficult better.

This may be a surprising conclusion, but I think it’s well defended. Just because a guy makes great plays, that doesn’t make him a great defender. There is more to it than that and Iglesias has yet to truly dominate in that facet of the game.