Sometimes, you have to dig deep into the numbers or read between the lines of public comments to find hints about changes players and teams plan to make. Maybe it's the unexpected decision of an entire team to turn their plate approach upside down, or to load up on curveballs. Perhaps it's the obvious addition of a new pitch, even when the player insists he hasn't done anything.
And sometimes, they make it extremely easy on you. We knew going into the season that the Cubs planned to move their outfielders deeper. How did we know? Because manager Joe Maddon told Cubs.com exactly that during Spring Training:
"To get guys a little bit deeper is probably the right thing to do. Keep the extra-base hit out of it and permit the single," Maddon said. "Now, when the ball bloops in front of you in the latter part of the game and the run scores, everybody goes nuts. Percentage-wise, it's probably better to play these guys a little deeper."
For an analytically-inclined team like the Cubs, that makes all the sense in the world. Balls over an outfielder's head are more likely to fall for doubles and triples. Balls that land shallower are almost always singles. As Maddon noted, the percentages favor the deeper player, even if the player -- often sensitive to pitchers not wanting poorly hit balls to fall in -- doesn't always like it.
That's particularly relevant to center fielder Dexter Fowler, the only returning Cubs outfielder playing in the same spot as 2015. (Jason Heyward has arrived to play right, while left field has seen Chris Coghlan [trade] and Kyle Schwarber [injury] cede time to a combination of Jorge Soler, Kris Bryant and Matt Szczur.) As Fowler told the Chicago Tribune, his first five-plus seasons with Colorado influenced him to play shallow, and it was his belief that such positioning actually unfairly hurt him with advanced defensive metrics.
He wasn't wrong. As August Fagerstrom noted here when identifying how the possibility of Fowler playing deeper helped save Jake Arrieta's no-hitter, of the 28 players with at least 3,000 innings in center field since 2009, only Matt Kemp rated more poorly than Fowler did, at -9 runs saved per 1,000 innings. It's not that Fowler doesn't pass the eye test -- he does -- it's that missed extra-base hits hurt more than missed singles.
Of course, teams say they're going to make changes all the time, and don't follow through. So, have the Cubs played deeper through the first month of 2016? It sure seems that way, and we can use Statcast™ to put some numbers to it. We have 22 center fielders who meet our qualifying standards of being on the field for 1,000 batted balls in 2015 as well as 300 in 2016. Last year, Fowler tied with Adam Jones for the shallowest average positioning, just a shade under 300 feet.
This year? Fowler hasn't just moved back, he's moved back farther than any other center fielder: a full 18 feet.

In terms of raw start point, Fowler has moved back far enough that a year after being the shallowest, only six center fielders are deeper than he is, and he's still among the deepest even when we account for the percentage of distance from home plate to the wall, which can of course vary from park to park. (Interestingly, Anthony Gose, like Fowler a shallow center fielder who was not looked upon kindly by advanced metrics, has also moved back this year.)
You can see that even more clearly when comparing Fowler's 2015 starting points to this season:
Gif: Dexter Fowler outfield graphic
So, has it helped? As Fagerstrom noted, it may have helped prevent a Devin Mesoraco line drive from ruining Arrieta's no-hitter, and as you can see from Fowler's chart of made plays vs. missed plays, just about nothing has gotten past him deep so far this year.

While it's absurdly early to put too much stock into any advanced defensive stat (which usually need a season or more to be of much use), it can at least be noted that Fowler has a +2 DRS this year after being at -53 over the past five seasons. It's not at all enough to conclude that he's going to be looked at favorably at the end of a full season, but it is a pretty good start in that direction.
While the advanced stats can tell a story, it's mostly common sense. Doubles and triples hurt more than singles. Whatever a team can do in order to prevent those more-damaging balls makes sense, and the Cubs clearly bought into that line of thinking this winter. Even if that means a few more singles -- and so far it hasn't been a problem, since the Cubs have allowed the lowest Batting Average on Balls in Play in baseball -- it's probably worth it. And since Fowler is likely to be a free agent this year, he'll certainly not mind it either if suddenly the advanced stats make him look a whole lot better.