It's still early in the year, but it's not that early anymore, because by the end of the weekend, the Yankees will have played a full one-quarter of their schedule. That means it's not so early that we can't take the time to point out that Brett Gardner has as many homers (seven) in 145 plate appearances as he did last year in 634 plate appearances. He has as many homers as Kristopher Bryant and Buster Posey do; he's got a higher slugging percentage (.504) than George Springer or Corey Seager do.
Gardner is nearly 34 years old, and he's long been known for his speed and defense more than for his power. Though he's twice had double-digit homers, he's never once had a slugging percentage higher than 2014's .422. Where in the world is this coming from?
In a lot of ways, the early 2017 version of Gardner is the embodiment of the home run trend we've seen across baseball: Hit the ball in the air, as hard as you can, pulled if possible, and don't worry about the strikeouts that almost always come along with it. It's a story you've heard repeatedly, and while it's too soon to say that this is what we will see all year, it's what we have seen so far.
Gardner has checked each and every one of those boxes. Let's take a spin through each one …

He's hit more balls in the air, or more accurately, fewer on the ground
Last year, Gardner's ground-ball rate of 52 percent was his highest since 2011; this year, it's down to 41 percent, which is just about where it was during his best slugging season of 2014. While his overall launch angle is up only about two degrees, his percentage of hits in his "line-drive zone" between 10-30 degrees is up from 25 percent to 35.1 percent. That's a big deal, because since 2015, his slugging percentage when he puts the ball in that zone is a massive 1.023. When it's lower than that, meaning grounders, it's only .338. When it's higher than that, so higher flies or popups, it's .167. There's a "sweet spot" for Gardner, and he's in it more often this year than he's been before.
He's hit it harder in the air
This is important, too, because his overall exit velocity really hasn't changed. Last year, his average was 85.4 mph, and this year, it's 85 mph. That's nearly identical, and it's below the Major League average of 86.9 mph. He's not Giancarlo Stanton or Miguel Sano. He's not a masher. But when he gets it in the air, which we'll define here as "anything other than a grounder," he is hitting it harder.
Last year, his non-grounder exit velocity was 88.3 mph; this year it's 91.1 mph. (That's harder than Michael Trout or Nolan Arenado.) His average distance on those in-air balls is up from 259 feet to 275 feet. (That's further than Anthony Rizzo or Victor Martinez.) Put another way, his hard-hit percentage (95 mph or harder) is up a little, from 24 percent to 28 percent, though that's still 211th-best in baseball, but his productive-hit percentage is up a lot, from 32 percent to 40 percent. That's 93rd, better than Stanton or Evan Longoria.
This is an extremely important point. He's not hitting it harder. He's hitting it harder where it matters.
He's hitting those hard-hit balls in the air to his pull side
In general, Gardner is pulling more batted balls. In 2015, he pulled 35 percent of his balls in play. In 2016, it was 34 percent. This year, it's 44 percent. But we're not interested in overall averages, we're interested in what happens when he gets it off the ground. Looking at only balls he's pulled, after having 65 percent of them on the ground in each of the last two years, he's had only 52 percent on the ground this year.
So what we have so far is a player who is hitting more balls in the air, hitting them harder, and pulling them to right field. A quick look at his career home run chart will easily explain where that strategy is coming from -- he's hit exactly one of his 70 career homers over the fence left of dead center -- and five of his seven homers this year have come at home, with Yankee Stadium's short right porch in play. It doesn't make the homers "cheap." It makes the strategy smart. If you're not Aaron Judge, why act like it? Play to your strengths.

He's striking out more
This all comes with a price, of course. Gardner is striking out 22.1 percent of the time, which would be a career high. Interestingly, it's not about swinging strikes as much as you might think, as his swinging strike percentage would be the lowest it's been since 2011. His called strike percentage, conversely, would be his highest since 2010. That's due to his extreme patience, which might suggest that he's waiting for the pitch he can drive.
While his strikeouts are up, it almost literally doesn't matter, because his value is up, too. His OPS+ of 134 is better than Jose Abreu or James Dozier. His wRC+ of 143 is better than Francisco Lindor or Carlos Correa. No one wants to whiff, but you'll absolutely take it for overall power like this.
So, is this a conscious effort? Is Gardner trying to be the next Daniel Murphy? If he is, he's not saying so, but the one change he is willing to admit to is where it gets interesting.
"I'm trying to make it a point to stay down on my legs a little more," Gardner told MLB.com earlier this week. "Just stay down on my legs and use my lower half."

It's not the first time we've heard that. When we asked hitters this spring about why they thought they'd hit more home runs in 2016, we got so many good replies that we weren't able to include them all. Two of the unused quotes left on the cutting-room floor were from similar speed-first players who echoed something along the same lines.
"Before if I hit the ball out front, I wasn't using my legs," said Philadelphia shortstop Freddy Galvis, who went from seven homers in 2015 to 20 in '16, and has now added 33 points to his slugging percentage in 2017. "Now I'm using my weight and lower half, and when I use it, the ball carries more."
That's similar to what Seattle's Leonys Martin, who added 10 homers and 65 points of slugging between 2015-16 said. "Before I was using my hands, but not my lower body. Last year, I was trying to use my lower body more and I found the power a little bit more."
Intuitively, it makes sense. The more of your body you use, the more power you ought to be able to get behind the ball. The harder you hit in the air, to your pull side, in a ballpark that's extremely conducive to such things, the better off you'll be. He won't out-slug Springer or Seager all year, of course. But he's off to a fantastic start, and he's been a huge part of why the Yankees have been so productive this year.