Around Christmas, when it first appeared that the Brewers would sign Figaro out of Japan (though there was some drama that delayed the signing), I wrote that his fastball was good, but that he simply tried to overpower hitters with it and I wasn't sure that would work in the Majors. However, his fastball so far this year is better than his fastball was in his first MLB stint and even in Japan, so while the approach explanation seems plausible, we have to adjust for the better fastball velocity. Still, looking at location is probably a good start.
Here are his strike zone locations on his homers, with the name and side of the plate of the hitters that hit the ball (remember Figaro is a right-handed pitcher).
Here are his average locations (there is an all pitches bubble right behind the fastball, as he locates his change and slider the same as his fastball on average)
It is important to note that all his home runs allowed have come at home. Miller Park is a hitter friendly park, especially for home runs, but he has also thrown over 2/3rds of his innings at home.
According to Katron.org, here are the homers he has allowed against right-handers:
When you look at movement data, Figaro's fastballs that he has given up homers on have more horizontal movement but less vertical movement. We did see that vertical movement did seem to matter when it came to whiffs versus contact fastballs on plus fastballs. However, Figaro's vertical movement on the home runs are a little closer than the average whiff than the in play pitches, with his average fastball close to the average whiff. The change between the average and home run fastball may be a plausible explanation (his home run fastballs actually had a little more spin on average than his average fastball).
So the problem seems to be fastballs that Figaro leaves up that have less vertical movement (and perhaps releases a little higher), or perhaps have less vertical movement because he leaves it up. However, this can be too easy of a narrative, so I wanted to look at the zone a little more, so I looked at all the pitches Figaro has thrown 2.5 feet (the middle of the plate) to 3.5 feet (the top of the strike zone) high, along with pitches that are within a half foot horizontally in the strike zone. It is all the pitches that would fit in the blue box in this graph of a blank strike zone:
I thought one reason may be because there were so many pitches in the middle of the plate, rather than on the "edge" of the plate. According to Bill Petti of FanGraphs, Figaro's edge percentage is 17.5 with a 31.2 heart of the plate percentage. The edge percentage is close to where Hiroki Kuroda and Travis Wood were last year, with Kuroda having a lower heart percentage and Wood having a higher percentage. Going by last year, it is a lower than average heart percentage, similar to some really mixed company in 2012 in Clay Buchholtz, Felix Doubrant, Ross Ohlendorf, and Dan Wheeler. Figaro works in the strike zone over 2.5 percent more than league average, and works arm side more (compared to the average right-handed pitcher in the Majors) than glove side, with down the middle being more frequent than glove side.
You can see that his slider and change locations are unorthodox and he doesn't get the slider to the glove side
The lack of secondaries, along with his failure to have success in the high part of the zone, seems to be why Figaro is giving up so many homers with a plus fastball. The lack of a good changeup is clearly a problem against lefties, and makes it unlikely (without some improvement in the pitch) that he will really have any success in the Majors except in some kind of platoon speciality role that the Brewers are not currently using him in.