What Happened to Justin Turner's Power?

Justin Turner is off to a hot start for the Los Angeles Dodgers, but after setting a single-season career high last season in homers, it's been mysteriously absent in 2017.

In the first season of a four-year, $64 million deal with the Los Angeles Dodgers, third baseman Justin Turner is off to a great start at the plate.

His 152 wRC+ and .403 wOBA both rank among the top 30 hitters in baseball, and he's already accumulated an fWAR of 1.9 off the strength of a .366/.442/.478 triple slash through 154 plate appearances.

There's one thing missing, though.

Turner has transformed himself as a hitter since landing in Los Angeles prior to the 2014 season, and part of that transformation involved a lot more homers. He's set a new single-season career high in homers through each of his first three years with the Dodgers, culminating with 27 in 2016.

But so far in 2017, he's trotted around the bases just once despite a fly-ball rate (40.9%) and hard-hit rate (34.8%) that don't look entirely different from what he's done in recent years. What's going on here?

Shift in Plate Discipline

Being patient and taking what the pitcher gives him hasn't been an issue for Turner in L.A. His walk rate has hovered around 8.0% throughout his tenure with the club, and his 7.8% walk rate so far this year shows us that not much has changed here.

What has changed, though, is how often he's chasing balls out of the strike zone. The below table shows his chase rate (O-Swing%) and swing rate on balls inside the strike zone (Z-Swing%), along with the corresponding contact rates since 2014.

Everything looks rather consistent, but there are a couple exceptions this year.

Year PA O-Swing% Z-Swing% O-Contact% Z-Contact%
2014 322 26.4% 68.0% 78.3% 87.9%
2015 439 25.4% 70.1% 77.6% 87.2%
2016 622 24.4% 66.0% 76.6% 86.9%
2017 154 29.1% 67.7% 74.7% 92.6%

Turner is making more contact on pitches in the strike zone, which is great, but there's also a noticeable increase in his chase rate, along with a corresponding drop in contact. These two events have helped keep his strikeout rate (13.0%) and swinging-strike rate (6.4%) awfully low, but it hasn't really helped his power.

When looking at the balls Turner is putting in play, his ground-ball rate (31.3%) has dropped about five percentage points, while his line-drive rate (27.8%) has taken most of that difference thanks to an increase of about four percentage points.

Line drives aren't a bad thing, but for a player looking to hit homers, fly balls are preferred. As mentioned earlier, Turner's 40.9% fly-ball rate isn't much different than it was in 2016. In fact, it's slightly above the 40.0% mark he produced last year.

So, the frequency isn't a problem, but how he's doing it seems to be the issue.

Performance on Fly Balls

While simply looking at a hitter's fly-ball rate and hard-hit rate is a good way to gauge their power potential, we sometimes have to dig a little deeper. A quick glance at Turner's numbers provide the perfect example.

When looking specifically at his quality-of-contact numbers on balls in the air, there aren't many conclusions we can draw from it. After all, his 38.3% hard-hit rate is very similar to his 2016 output (38.8%), while his 14.9% soft-hit rate is a slight improvement on last season's clip (15.3%).

However, it looks like the biggest difference between his start in 2017 and last year's performance has been the direction in which these fly balls are, well, flying.

Not Pulling the Ball Enough

When compared to last year, Turner has used the middle of the field for balls in the air much more frequently in the past. The below table shows how often his fly balls have been pulled (Pull%), gone up the middle (Cent%) and hit to the opposite field (Oppo%) since becoming a Dodger.

Year Pull% Cent% Oppo%
2014 15.4% 44.6% 40.0%
2015 20.9% 37.4% 41.7%
2016 20.8% 28.4% 50.8%
2017 17.0% 46.8% 36.2%

There's nothing wrong with hitting balls to center field, but if you want homers, it's a bad idea since this is generally the deepest part of any ballpark.

In 2016, Turner pulled 16 of his 27 homers, and with just a 23.6% fly-ball rate on his fly balls to center, his home-run-to-fly-ball ratio (HR/FB%) was 42.1%. He did hit 6 homers out toward center, but his HR/FB% went all the way down to 11.5% on his fly balls to the middle of the field despite a fly-ball rate of 34.0%.

Upon taking a look at the same data for this season, we're starting to get an idea as to why he's having success everywhere but the homer department.

His HR/FB% on balls he's pulling is just 12.5%, and his fly-ball rate is only 20.0%. While his ground-ball rate in this situation has dipped below 50.0% for the first time in his career, he's hitting pulled line drives at a 32.5% rate, which is nearly 10 percentage points higher than what he did last year.

On balls he's hitting toward center, both line drives and ground balls are down, but his fly-ball rate is a career-high 48.9% and is accompanied with a drop in hard-hit rate (33.3% this year, compared to 39.9% in 2016).

Moving Forward

Despite the lack of general power, Turner has used some good fortune -- in the form of a .421 BABIP -- in order to enjoy such a great overall start. Although his current homer rate is getting close to the stabilization point, according to FanGraphs, it's hard to discredit the positive steps he's taken in this department over the past few years after just 150-plus plate appearances this season.

However, that BABIP is going to normalize sooner rather than later. For him to start hitting homers at the rate we've gotten used to seeing, it appears he'll need to be a little more aggressive in his approach at the plate and look for pitches he can put in the air toward left field.