Let's provide two facts about Ryan Zimmerman that initially don't seem to make a lot of sense when paired together, facts that could go a long way toward explaining his 2016 season and projecting what Washington may expect in 2017.
Fact No. 1: Zimmerman crushed the ball in 2016
His 93.7-mph average exit velocity was the 12th best of the 375 batters who had at least 100 tracked balls in play -- better than Josh Donaldson and Paul Goldschmidt. Sluggers like Nelson Cruz and Jose Cabrera are in the Top 5; slap hitters like Billy Hamilton and Dee Gordon are in the bottom five. It's good to hit the ball hard. Obviously.
Fact No. 2: Zimmerman had a rough 2016
His .218/.272/.370 line was the sixth weakest of the 270 hitters with 400 plate appearances -- ahead of only middle infielders like Adeiny Hechavarria and Ketel Marte, plus two guys who can't even find a job for 2017 so far in Erick Aybar and Alexei Ramirez. If it's not good enough for a shortstop, it's certainly not acceptable for a first baseman who still has half of a six-year, $100 million contract remaining.
You can't really dispute either of these facts, yet they don't really seem to square with one another. How can someone who hit the ball so hard find so little production from it? Is there any reason to believe that Zimmerman will rebound in 2017, as the Nationals clearly hope he will because they made no moves to upgrade at first base (or at second, pushing Daniel Murphy over)? Let's find out.
First, let's show you what we mean about how odd it is to find a player who hit the ball that hard and struggled so much. The chart below shows the relationship between exit velocity and Weighted On-Base Average (wOBA) -- a stat that's just like on-base percentage, except it gives additional credit for extra-base hits rather than treating all times on base the same. We're showing those 375 hitters with 100 balls in play, and the trend between velocity and production is clear: Harder is better.

So that's a clear relationship, and you can see how Zimmerman stands out as an outlier. Rather than producing like Yoenis Cespedes or David Ortiz, who had similar exit velocities, he produced like Tucker Barnhart or Ezequiel Carrera, who hit the ball far more lightly. While we're only showing production on contact here, the answer is not lack of contact -- because while Zimmerman did strike out more in 2016 than usual, his 22.3 percent whiff rate was similar to the 21.1 percent rate across the bigs.
Instead of average, which can be skewed by extremely high or low results, let's shift to frequency. Was Zimmerman's average exit velocity so high because he had a few very hard-hit balls, or because he was regularly hitting the ball hard? It's better for him if it was the latter -- and as it turns out, it was indeed the latter. Last season, 187 batters had 100 or more balls in play with an exit velocity of at least 95 mph. As you can imagine, that's a very good thing to do: The Majors collectively hit .538 on balls hit that hard.
Zimmerman hit 51.6 percent of his balls in play at 95 mph or above, more than half. That's excellent. Of those 187 players, it ranks 20th -- roughly the same rate as Mark Trumbo, Yasmani Grandal and Jose Bautista. So we know Zimmerman's balls in play were hit quite hard more than half the time, and at a rate that would be in the top 11 percent in baseball.

But what happened on those hard-hit balls tells you a different story. On those 95-mph balls in play, look at what happened for Zimmerman (ranks out of 187 players):
• 175th in batting average: .476
• 165th in BABIP (i.e., batting average on non-homers): .416
• 167th in slugging percentage: .883
• 150th in launch angle: 7.9 degrees
Despite being near the top of baseball in how often he hit the ball hard, which suggests his bat speed remains intact after years of injuries, Zimmerman is near the bottom of Major Leaguers in how much success he found when he did hit the ball so hard. Why? Bad luck? Good defense? Something else?

It's that last line, launch angle, that you ought to focus on. We consider a launch angle of 10 degrees or below to be grounders; 10 to 25 degrees to be line drives; between 25 and 50 degrees are fly balls, and 50 degrees and higher are popups. As we've talked about regularly, you can't slug on the ground. Examples of players hitting more flies and finding more power like Murphy, Christian Yelich, Gregory Polanco and Trumbo are all over the place.
Though he hit the ball hard, Zimmerman had a pretty low launch angle, which is to say he was hitting hard-hit grounders. When viewed in this context, his numbers above make a lot more sense. While the Major League average for all batted balls 95 mph and up was .538, the average for batted balls 95 mph with a launch angle of 10 degrees and under was .470 -- just about exactly the .476 Zimmerman had.
So Zimmerman is doing himself no favors by putting his hard-hit balls on the ground, but he's not being unfairly penalized for them, either. The real problem here, as it turns out, isn't just what happens when he hits the ball hard. It's what happens when he doesn't. As we said before, 51.6 percent of Zimmerman's batted balls go more than 95 mph. That means just more than 48 percent do not. If hard-hit balls on the ground aren't helping Zimmerman out as much as you'd think, you can imagine what softly-hit balls on the ground are doing.
Consider this: 401 players had at least 50 batted balls of 95 mph or less (that were tracked by the Statcast™ system, anyway, as it's known that some softly-hit balls were not able to be tracked). The league average was .242 on those tracked balls, which is understandably low. The leader was Boston's Sandy Leon at .393, certainly a luck-based outcome that fuels trepidation about him being able to repeat his performance.
Of those 401 players, the bottom two were part-time catchers Roberto Perez and Ryan Hanigan ... and the 399th player, with a .129 average, is Zimmerman. He got just 18 hits out of his 140 softly-hit balls in play. No regular player in baseball got less out of the batted balls that don't usually yield much anyway. So for 2017, the question isn't if Zimmerman can hit the ball hard. He can. The question is if he can get it off the ground. If he can't, he may not be Washington's first baseman in 2018, no matter what his contract says.