Domonic Brown was one of the best prospects in baseball, in fact, according to Baseball America, he was the 4th best prospect in baseball in 2011, where he would split the year between AAA and the Majors (he debuted in 2010). It was the 3rd straight year that Baseball America considered him one of the top 50 prospects in baseball (starting in 2009, after he spent 2008 in A-ball). However, from 2010-2012 Brown had an 89 OPS+ in the big leagues in 492 plate appearances with a .269 BABIP. Along with defense that rated poorly, Brown looked like he was a high profile bust. However, so far this year, he has a 130 OPS + with a .281 BABIP in 331 plate appearances (all numbers are before Wednesday, where Brown hit another homer, this time on Jason Grilli).
The OBP actually isn't much different (.315 to .320), so we wouldn't expect to see a different swing map:
His whiffs are no different in location so far this year (though they are on slightly slower pitches so far this year), but his contact shows a lot of the changes we have saw with the average swing.
When looking at hot starts or good stretches, even if they are over a long period of time and don't appear to be BABIP related, we need to get context when it comes to average pitch location and release points
So really on average he is seeing pitches in the same location, but he is actually seeing slightly slower pitches this year. He is also seeing more pitchers that are either closer to the center of the rubber or left-handed, which we would expect to make him worse. We would also expect slower pitches to make him worse as well since his contact is coming on harder pitches than his whiffs, but apparently it isn't. It is not that he is swinging at less pitches out of the zone or less pitches in general, he is actually swinging at more pitches both in and out of the zone. This explains the real lack of OBP difference, but what about the raw bat speed or ability to hit elite pitches?
On pitches over 95 MPH +:
2013: 6.05 %, 8 swinging strikes, 13 contact plays
Pre-2013: 4.9 %, 13 swinging strikes, 19 contact plays
So he is seeing more high velocity pitches, but his ratio is a little worse so far this year. It doesn't seem that he has all the sudden gained any kind of talent. The data still seems to support the idea that he is directing his swings on pitches that are more up in the zone, an approach change (since he isn't being pitched higher on average).
Since the change has been in power (his average batted ball distance is about 10 feet higher), it is I think important to look at where he is hitting the ball. To do this, here are all the pitches Brown has made contact with (in fair territory) in 2013 in the strike zone, labelled with where the ball went:
Not only does the 2013 graph show that he doesn't like or doesn't make contact with hardly any low pitches, he is also an extreme pull hitter. He is pulling a lot of pitches that are on the outside part of the zone. Here are the balls Brown made contact with before the 2013 season:
This year overall, he is pulling more balls, using the middle of the field the same amount, but going the other way less than he was before 2013. The chart shows that Brown was pulling everything on the inside part of the plate before 2013 as well, and was still pulling a lot of the balls on the outside of the plate. Just looking at the charts, I don't think you can really see a big difference of any kind.
This means that we have, from what I can see, two choices. 1. Brown's half of season is fluky, and his real talent level is closer to his pre-2013 numbers rather than the future star many prospect evaluators had him labelled as. 2. Brown's approach change to just swing at higher pitches on average (or, to just swing at more higher pitches since he doesn't have an improved swing rate) have caused him to bring out his natural strength. I don't think the data gives us much wiggle room beyond the two choices. Perhaps it could be a mixture of the two, as his 24.4 HR/FB % probably isn't real, though he is hitting less grounders (which I think supports option 2), and he will regress some, but the slight approach change has helped him hit for more power.