Is Brad Miller's Power Surge From 2016 Sustainable?

Before the 2016 season, Brad Miller was seen as an unspectacular, but certainly valuable player who can give a team solid at-bats. He proved this during his three seasons with the Seattle Mariners, where he logged time at shortstop, second base, and all three outfield spots while posting wRC+ numbers of 106, 87 and 105.

He was shipped to the Tampa Bay Rays in November of 2015, which has ended up being more fruitful than expected.

Miller entered last season with 29 career home runs, but more than doubled that by smashing 30 over the fence for Tampa Bay, which included him switching from shortstop to first base. So, he transformed from a serviceable shortstop into a slugging first baseman.

That was a wonderful surprise for both the Rays and Miller, but is this power surge sustainable? There is some evidence saying it certainly can be.

The Numbers

Could we have seen this coming? Let's take a look at some of his numbers from each season.

One of the biggest positives here is that Miller's underlying numbers didn't change very much -- outside of his Isolated Slugging Percentage (ISO). With his walk rate and strikeout rate from 2016 looking rather similar to what he'd done in the three seasons prior, it's telling us that this power uptick was more natural than being cultivated in unlikely scenarios.

His 111 wRC+ is a new career high, but it didn't change much despite such a drastic increase in homers. That can be attributed to his inability to get on base consistently, which can be seen from his walk rate and OPS. Either way, he's performed as an above-average hitter in three of his first four MLB seasons, and this newfound power only makes that better.

The steady increase in doubles from year-to-year show his power was potentially on its way, as he was hitting the ball with more authority overall.

Lucky Home Runs?

While a 500-foot bomb and a wall-scraper look the same in a box score, they are not created equal. The 500-footer is always a home run, but a wall-scraper is at the mercy of the dimensions of a stadium, which also provides outfielders a chance to bring it back into the field of play. According to ESPN's home run tracker, though, all of Miller's home runs would have left Tropicana Field.

This is significant because Miller is playing 81 games there. Some barely got over the fence, but he still hit legitimate home runs in a stadium where he'll play most of his games -- where he also won't have to worry about the wind or outside elements, for better or worse.

Miller hit 11 homers that were defined by ESPN as "just enough", which means the ball cleared the fence by less than 10 vertical feet or landed less than one fence height beyond the field of play. Miguel Cabrera and Joey Votto also hit 11 "just enough" homers in 2016.

On the contrary, healso slugged 19 "no doubt" home runs, which is defined as clearing the fence by at least 20 vertical feet and landing at least 50 feet past the fence. So, even if every single one of those "just enough" homers didn't end up getting over the fence, Miller still would've nearly doubled his previous single-season career high in the department, which was 11 in 2015.

The power appears to be for real.

Where Did it Come From?

Finally, the million-dollar question: Where the heck did this power come from?

The answer to this is hidden in an altered approach at the plate. Below is a GIF of Miller hitting a homer as a member of the Mariners during Spring Training.

Now, notice the change in his leg kick as a member of the Rays last year.

That's a big deal, especially in terms of power. The short leg kick allowed him to get to the ball quicker, but is more conducive to hitting line drives than home runs. The higher leg kick helps generate more torque, which gets the bat through the zone with more power to hit the ball harder overall.

The evidence can be seen in the difference between his line-drive rate (LD%), fly-ball rate (FB%), pull rate (Pull%) and hard-hit rate (Hard%) between 2015 and 2016.

Staying consistent with this approach and stance is the biggest key for him moving forward for his power to be sustainable.

Miller has always been a valuable player, and while he may never be a star -- unless he improves in all facets of his offensive game -- he's still a valuable commodity for the Rays, and likely made them feel comfortable in trading away Logan Forsythe. This power surge appears to be the real deal, and if he's able to repeat it in 2017, his value will only increase.