So, Danny Espinosa Has Hit 18 Homers

It took me until Saturday’s two-homer game to realize that OMG, Danny Espinosa has gone bonkers. It took him until April 29th to hit his first home run of the season. He then hit five in May, nine in June, and already has three in July. Danny Espinosa. He of the career high of 21 home runs set all the way back in 2011, his first full season, in more than double the plate appearances. He who we expected, nay, knew, was just a temporary placeholder for top prospect Trea Turner, who was surely going to be up with the big club early in the season and push Espinosa to a bench role.

So what the heck has gotten into the 29-year-old Espinosa? In my ebook Projecting X 2.0, you learn that there are three components driving a hitter’s home run tally — strikeout rate, fly ball rate, and HR/FB rate. So let’s focus on those components to identify precisely what’s fueling Espinosa’s power surge.

The strikeout rate is at a career best mark. Not by a whole lot, but improvement is improvement. He has managed such a feat by reducing his SwStk% and O-Swing%. Both rates are at their best since his 2011 season. He is also swinging less frequently, which has boosted his walk rate. So the strikeout and walk rate peripherals support his improvements. Whether they last is anyone’s guess, but it hasn’t been a fluke so far.

We next move on to the fly ball rate, which gives us our first major explanation. Since we’re on FanGraphs of course, how about a graph of his FB% trend?

And there it is. It’s simple really — all else being equal, hit more fly balls, hit more homers! And that’s exactly what Espinosa is doing. Usually the strategy is bad for BABIP, and sure enough that mark has fallen to just .259. But it’s great for power! His FB% which has always stuck in the mid-to-high 30% range, has suddenly spiked to 47%, a hefty increase.

Last, we’ll check in on his HR/FB rate. Obviously, we have to assume it has risen. But by how much and is it sustainable? Let’s look at yet another graph:

Espinosa never posted a HR/FB rate above 14.1%, a career high set just last year. But this season, he’s all the way up above 20% at 21.2%, about 50% greater than his previous career high. What do I immediately check when I see significant changes in a hitter’s HR/FB rate? His average home run and fly ball batted ball distance, of course. And it doesn’t paint a pretty picture. His current 275 foot distance mark represents a career low! Throughout his career, his distance has remained rather consistent, ranging between 279 and 286 feet. So it’s rather surprising and head scratching to discover that his distance actually sits at a low all the while his HR/FB rate stands at a career high.

One of the important components of my xHR/FB rate equation is average absolute angle, which indicates how close to the foul lines a hitter’s fly balls and home runs are hit. Since those locations represent the shortest part to the fence, hitting them there would increase a hitter’s HR/FB rate. Unfortunately, I don’t have the data from this year, so as a proxy, I have been looking at a hitter’s fly ball Pull% and Oppo% marks. If Espinosa is pulling and/or going the opposite way more frequently than in the past, that would certainly explain some of the disconnect between his distance and HR/FB rate.

Sure enough, Espinosa’s fly ball Pull% is at a career high of 35.3%, the first time it has been above 30%. However, his Oppo% is down a corresponding amount. Adding the two together yields a nearly identical Pull + Oppo rate as last year. Since we know the average distance, I feel like the distinction between pulled and opposite field fly balls shouldn’t matter. But perhaps it does. Maybe that would affect the third xHR/FB rate component, standard deviation of distance (SDD). It’s possible that he’s hitting his pulled balls much further than his oppo balls, which would keep the distance the same, but increase his SDD. Without the data in hand, I’m just speculating.

So we have learned that Espinosa’s power spike is being accomplished in a less sustainable way than I like to see. I prefer to see an increase in distance, rather than a change in approach, this time being pulling the ball more. He might not continue pulling the ball as often and he doesn’t have the strong distance to fall back on. I doubt anyone is buying Espinosa, so all an owner could do is hold and hope this approach lasts all year. I expect some major regression in his HR/FB rate over the rest of the season and it’s very difficult to maintain 20% HR/FB rate with such a subpar distance.