Oakland A’s infield still dominating defensive metrics

Oakland A’s fans already know they’re watching one of the best defensive infields in the sport, and now there are some new numbers to back up that claim.

On Monday, SABR released the midseason update of their defensive metric, called SDI for SABR Defensive Index. The A’s fared quite well in the rankings, with three of their infielders leading their respective positions in the AL and placing within the top 13 of all AL defenders at any position. The overall AL list:

1. Byron Buxton, CF: +7.6
2. Marcus Semien, SS: +7.3
3. Mookie Betts, RF: +7.1
4. Roberto Perez, C: +6.3
5. Kevin Kiermaier, CF: +6.0
6. Matt Chapman, 3B: +5.8
7. DJ LeMahieu, 2B: +5.7
8. Willy Adames, SS: +5.5
9. Max Kepler, RF: +5.4
10. Marwin Gonzalez, 3B: +5.0
11. Jake Marisnick, CF: +5.0
12. Alex Bregman, 3B: +4.9
13. Matt Olson, 1B: +4.7
14. Tyler Naquin, RF: +4.7
15. David Fletcher, 3B: +4.6

Split them up by individual position, and Semien, Chapman, and Olson each lead their respective groups within the AL. Semien has a particularly wide lead over the next AL shortstop.

Of course, the news isn’t all great, as Jurickson Profar ranks last in the entire majors at 2B, also by a big margin. That drags down the A’s argument as the best overall defensive infield, but it doesn’t change the fact that no other team boasts three league-leading performers.

The main challengers come in the National League. SABR ranks Arizona shortstop Nick Ahmed as the top defender in the majors at any position, nearly three points higher than the NL runner-up and more than 50% higher than AL leader Buxton. Arizona also has the top 1B, with Christian Walker edging out Olson. However, they haven’t had anybody play enough at 2B to qualify for SABR’s list, and their 3B bears a negative rating.

The Cardinals have a better case than the D’Backs. They have the overwhelming 2B leader in Kolten Wong, the shortstop runner-up in Paul DeJong, plus a positive value for 1B Paul Goldschmidt, though Matt Carpenter has a negative rating at the hot corner. The Marlins also have a good case, with positive value at all four positions and strong value at SS/3B.

But it’s the Cubs that might lead this debate right now. They rank top-5 in the NL at all four positions, with Anthony Rizzo, Addison Russell, Javier Baez, and Kris Bryant. Rizzo and Baez have particularly high marks.

So for now, we might have to settle for calling the A’s the best defensive infield in the AL, at least until they shore up second base. Of course, we’re talking about half-season samples of defensive metrics, which is far from a precise discussion, but the eyeball test firmly agrees that 2B has been a disaster in Oakland, and there’s nothing too shocking in those other numbers either.

Other metrics

But wait! There are other metrics out there. Do they corroborate the findings of SABR?

Looking at Defensive Runs Saved on Baseball-Reference, Chapman still leads all 3B in the majors at +10, with only two others even exceeding +5 right now (Brian Anderson, Jeimer Candelario). Olson doesn’t lead at 1B, but he’s clearly among the top group, which is mostly made up of NL players (he’s at +3, with the MLB leader at +5). Semien falls to 15th place among shortstops, with a relatively pedestrian +3 runs.

The story is different at FanGraphs, though, using Ultimate Zone Rating. There Semien leads AL shortstops again, stands just a hair behind the NL shortstop leaders (DeJong and Miguel Rojas), and ranks ninth among all major leaguers at all positions (+6.1). Chapman is behind him at 15th overall (+5.0), trailing only Nolan Arenado among third basemen. Olson is 25th overall (+3.2), barely trailing Rizzo as the top 1B.

As for Profar, DRS (-8) is harder on him than UZR (-2.7), but both scales say there are a couple dozen players in the majors who are worse (at various positions, not just 2B). Moving back to SDI for a moment, the short list of players who rate worse than Profar is quite interesting. Among them is catcher Jonathan Lucroy, while Mariners backstop Omar Narvaez just edges him out too. Rockies CF Ian Desmond and Mets SS Ahmed Rosario have by far the worst scores, both in negative double-digits, though to be fair what is Desmond doing in CF? The unexpected twist is Red Sox CF Jackie Bradley Jr grading slightly worse than Profar.

Pitchers

Speaking of unexpected twists, here’s another one. Pitchers are technically part of an infield’s defense too, and the A’s have a couple who rank highly on SDI. Coming in 16th in the AL is newcomer Homer Bailey (+0.6), 12th is Chris Bassitt (+0.7), and 6th is ... Brett Anderson at +0.9? No, that can’t be right, and to prove it I’ll look at DRS, which has Anderson ... tied for 13th in the majors at +2? Huh. (Note: UZR doesn’t grade pitchers.)

Surprise outfielder

While the A’s infield gets all the attention, one of their outfielders is quietly putting up nice marks with the glove — and it’s not Ramon Laureano. Oakland’s CF has negative marks on DRS and SDI, and is neutral on UZR, despite his highlight-reel ability.

No, the standout is LF Robbie Grossman, who also fares well in Statcast’s new Jump Score. He ranks 17th among all AL players in SDI, and leads AL left fielders (+3.9). He’s 26th in the majors in UZR (+3.1), just behind Olson, and only two left fielders have him beat there (David Peralta and Tommy Pham). And he carries a positive value in DRS as well (+2), though not as extreme as the other metrics.

Should we really be that surprised, though? Grossman had atrocious metrics in 2016, but the rest of his career has been consistently neutral, making that one stinker look like the obvious outlier in a statistical area that takes multiple years to become reliable. Of course, by that same token we shouldn’t get too excited by his recent statistical improvement, but the point is that there’s no reason to look at him as a defensive negative. He’s perfectly fine out there, and at his best maybe even above-average.

But still

At the end of the day, though, this post is just some fun with numbers. Don’t read too much into half-season samples of this stuff.

The real takeaway here is Semien. His huge metrics last summer came as a shock to everyone, but it was still just one season. Now he’s doing it again, which makes the praise more reliable, and if he does it again next year then he’ll end any possible doubt. Of course, the eyeball test also backs the assertion that he’s become a quality defender, but to see the numbers agree for two straight seasons is even better.

Beyond that, we already know that Chapman and Olson are great and we don’t need metrics to tell us that. With them, it’s more the entertainment value of how high they can make those numbers go. And as for upstarts like Grossman and Anderson, it’s not like they’re going to suddenly win Gold Gloves, but it’s always fun to see A’s players grade out well at stuff.

The bottom line is that the A’s are a good defensive team. They’re not perfect, and there are a couple of weak positions in the lineup, but overall their fielding almost certainly helps them more than it hurts.