The All-Defense Free Agent Gambit

A nice generic platitude is that free agency gives you a chance to completely remake your team. That’s an aspirational vision, but I mean, come on. Free agency gives you a chance to sign a really good player, or a few okay players, or even Daniel Descalso (I kid, Cubs fans, I kid).

In reality, completely remaking your identity mostly doesn’t happen. Teams don’t generally overhaul their image in free agency; they add pieces around an existing core they’ve carefully shaped. If they’re lucky enough to land a superstar, they’re at the mercy of fate as to which superstar is available; if you want to sign a 6 WAR third baseman this year, well, keep looking.

It only mostly doesn’t happen, though. This year, I think there’s a rare chance to actually change the identity of your team in free agency. More specifically, I think teams should look at turning their squad into a defensive powerhouse. That’s mostly not a one-year undertaking, but this time, I think it is.

The first key factor that makes this strategy workable is an accident of personnel. You might have heard of the best defensive shortstop on the market. Indeed, Andrelton Simmons is one of the best defensive shortstops of all time, period. His range, arm, hands, and baseball instincts are all off the charts. Whichever team signs Simmons will immediately have one of the best defenders at the position, a down 2020 notwithstanding.

Simmons is the best infield defender of the past 10 years. The best defensive second baseman over that same span isn’t quite so clear, but Kolten Wong is certainly near the top of the list. He’s been one of the very best defenders at the position in each of the last three years, including a blowout 2018 that, naturally enough, is the only year he didn’t win a Gold Glove despite outstripping his other two seasons by every metric.

With two strokes of a pen, a team could sign Simmons and Wong and have the best up-the-middle defensive infield in the game. I’m exaggerating slightly, of course: most contracts need more than one signature, and most names need more than a single pen stroke to sign. I’m certainly not exaggerating, however, when I say it would be the best defensive combination. Whatever their other shortcomings, Simmons and Wong look better than any other pairing in the game.

The next factor that makes this work isn’t quite so team-agnostic. To effect this defensive makeover, you have to cast your current middle infielders aside. For some teams, that’s hardly an issue, but the Padres are hardly going to move on from Jake Cronenworth and Fernando Tatis Jr., just as the Braves aren’t kicking Ozzie Albies and Dansby Swanson to the curb, and the list goes on.

To get a quick idea of who would be willing to tear everything down and start over, I looked for the teams with the worst Depth Charts projections at second base and shortstop. That only considers rosters as they exist today, so the Yankees, for example, have Tyler Wade and Thairo Estrada at second base. That’s a feature, not a bug: we’re looking for teams who have holes, whether due to attrition or there simply being no good options to begin with. Here are the bottom 10:

Not all of these teams really fit the exact blueprint I’m looking for. The Brewers, for example, seem unlikely to swap Wong in for Keston Hiura. The Marlins aren’t likely to cut team captain Miguel Rojas to add Simmons. Finally, the Reds seem set on Mike Moustakas at second base. The other seven, though, should at least consider making a wholesale change.

There’s one further hurdle: an elite defensive infield isn’t worth much if you don’t have pitchers who can feed them grounders. It hardly matters who plays defense behind Josh Hader, for example. It hardly matters, for different reasons, who plays behind Matthew Boyd; if he doesn’t strike the opposing hitter out, he’s probably walking them or allowing a ball in the air. If we’re going to overhaul a team to center their identity around defense, the pitching staff needs to be in place already.

How should we figure out which staffs could most benefit? The laziest — and least correct — way would be to simply look at 2020 groundball rates. That’s one data point, but it misses a lot of things. First, a pitcher’s 2020 performance isn’t the same thing as what we should expect from them going forward. Second, a team’s 2020 pitching staff isn’t the same thing as its 2021 pitching staff. Teams used a tremendous amount of minor league depth this year, and the normal free agency ebb and flow of rosters applies to pitching as much as it does to position players.

To deal with those two complications, I did a little projecting. First, I used career groundball rates to create projections for 2021. I used a season-to-season regression-based method and found that you should apply roughly 110 plate appearances of league average performance to your data to come up with a true talent estimation. Luckily, that lines up with an old but still useful examination by Derek Carty that found the number to be 105. That’s close enough for my purposes, particularly given that we’re not trying to hit a bullet with a bullet here, merely to give a rough idea of groundball rates.

Armed with that data, I turned to our Depth Charts rosters and playing time projections for 2021. I used each player’s projection to 2021 to approximate how many balls in play they would allow, then used my groundball rates to convert that into grounders. From there, I simply worked out how many grounders each team projects to allow across their entire rotation and bullpen.

That only gets us most of the way there, because grabbing and downloading our Depth Charts projections doesn’t allocate innings perfectly. To handle this, I normalized each team’s projected innings totals to 1,458 innings, 162 nine-inning games. Baseball teams see a lot of grounders — more than one per inning, in fact. A few teams stand out:

Why are the Rockies so far ahead of the pack? Coors simply leads to so many baserunners that they get more bites at the apple than everyone else. It’s a strange way to lead the league, but is nonetheless an argument for a good infield defense — though that’s somewhat counterbalanced by the fact that Rockies hitters come to the plate more often.

Other than the Rockies, teams with higher groundball totals mostly come down to pitcher profile. The league average is around 1,920 grounders per team, which means that the Giants have 80 extra opportunities to deploy good infield defense, one every other game. That’s a meaningful edge, which means the Giants and Orioles combine the two prerequisites — grounders to field and shallow depth charts to displace — that best line up with my plan.

The Orioles are an odd case — getting rid of José Iglesias at the same time that you’re planning on pivoting to defense is weird — which means they would probably pursue only Wong in free agency, not both defenders. That leaves the Giants as the only team that, per my filtering, should consider the all-defense gambit.

Of course, there’s one other interesting case. The Mets have players they like in the middle infield, but they aren’t great fits for a team that allows so many grounders. Robinson Canó is hardly a defensive stalwart at this point in his career, and the Amed Rosario/Andrés Giménez time share is long on potential but short on actual results. They probably won’t do it — but shifting Canó to third, trading Rosario and J.D. Davis for something useful, and bringing in a defensive overhaul would leave most of their potent offense intact while turning a separate weakness into a strength.

Will anyone go whole hog and sign two of the best defensive middle infielders of the last decade? Probably not! But before either has signed, it’s fun to think about whether anyone should, and if the Giants or Mets feel so inclined, they could be the rare team that does remake their identity in free agency.