A few days ago, a couple of our Twitter followers were surprised when they noticed the difference between the Defensive Runs Saved totals for the Rockies third basemen and the Cardinals third basemen.

Ryan McMahon and Joshua Fuentes have played Nolan Arenado-like defense at third base. But Arenado hasn’t been Arenado-like this season, at least not by our measures. Fuentes and McMahon are ranked 2nd and 3rd in Defensive Runs Saved at the position. Arenado is only slightly above average.

At SIS, we have the ability to break this down and look at how an infielder is doing on balls hit to their left, right at them, and to their right. We can look at plays on which the chance to record an out is greater than zero (we’ll call that “opportunities”) and see how often the player recorded at least one out on the play.

And in doing that, that can help to explain why the gap between McMahon, Fuentes, and Arenado is large this season, specifically as relates to one area – balls hit to their left.

Comparing them on balls hit to their left

The thing that most drove Nolan Arenado’s Defensive Runs Saved numbers throughout his Rockies career was how he fared on balls hit to this left.

You got used to seeing plays like this

From 2013 to 2020, he averaged being 14 plays above average on balls hit to this area In other words, if there were 200 balls hit to his left, and the average fielder got an out on 100 of them, Arenado was 14 better than that … in other words, 114.

But in his first season with the Cardinals, he’s only 2 plays above average on balls hit to his left.

In simplest terms, there has been a little more of this:

and less of this

But what McMahon and Fuentes have done is replicate Arenado’s past performance on balls hit to their left.


McMahon & Fuentes vs Arenado – On Balls Hit To Their Left- 2021 Season

Player Outs Made/Opp Plays Above Avg
McMahon/Fuentes 126/218 (58%) +19
Arenado 84/180 (47%) +2

(All stats entering Wednesday)


They’re not just better than Arenado this season. They’re a lot better.

Here’s two nifty plays by Fuentes (now in the minors) going in that direction


and here’s one from McMahon, who ranks second in Defensive Runs Saved at the position and first in Defensive Runs Saved overall because he’s been just as good at second base.

There are other anecdotal numbers that illustrate the stark difference this season.

– McMahon and Fuentes have combined for 25 Good Fielding Plays at third base this season (think “Web Gems”). Arenado, who typically leads third basemen in the stat, has 16.

– Arenado also has 21 Defensive Misplays & Errors, meaning this could be the first time in his career that he’s had more Misplays & Errors than Good Plays (the Rockies duo has 24 Misplays & Errors).

– Additionally, Arenado has converted 8-of-28 double play opportunities (29%). His conversion rate is usually 60% or higher. McMahon and Fuentes have converted 21-of-29 (72%).

– Lastly, when Arenado plays in a defensive shift, he’s had considerably more difficulty getting outs than he usually does. He’s at -5 Runs Saved on shifts. He saved 22 runs on shifts from 2018 to 2020.

McMahon and Fuentes have saved 7 runs combined on shifts at third base this season.


It would be wholly unfair to write off Arenado though, so let’s point out a couple things. He’s having his best year saving runs as relates to bunt defense (3 Runs Saved). He’s also fared better than McMahon and Fuentes on “straight-on” balls. There’s a long track record of success that makes us think that Arenado is still a great glove.

But the gaps created in all the other areas make it pretty clear that the Rockies have not missed a beat defensively at third base and their pair has outperformed Arenado in that regard this season.