Mookie Betts, Mike Trout, J.D. Martinez, Aaron Judge, Lorenzo Cain, Andrew Benintendi, and Giancarlo Stanton. These are the only seven outfielders that have been better than Diamondbacks left fielder David Peralta in fWAR. Peralta is in no way a hidden gem, but finds himself consistently under-the-radar compared to baseball’s marquee names.
A former pitcher, minor league release, and independent baseball player, Peralta has a great story that is well known. He’s been a well established outfielder in the majors since 2014, rotating between good and great seasons. Narrowing things down a bit, he’s in no question baseball’s hottest hitter at the moment. No player in the month of August is displaying a higher batting average, ISO, slugging percentage, or wRC+ for the month. Additionally, no player has accumulated more fWAR this month (his teammate Paul Goldschmidt is the closest one).
Top wRC+ in August
|J.D. Martinez||Red Sox||89||218|
|Jose Abreu||White Sox||79||179|
|Mookie Betts||Red Sox||93||177|
|Xander Bogaerts||Red Sox||73||176|
Putting this month into perspective for his career, he’s in the middle of the best month of his major league career and it isn’t even close.
David Peralta wRC+ by month
Admittedly, there’s an easy-to-find culprit for this surge in offensive production. He’s just simply hitting the ball harder. No player has a higher hard-hit rate this month than his mark of 66.1 percent (Kole Calhoun is next closest at 60.3 percent, making the difference between first and second greater than the difference between second and sixth). Adding in an improved K-rate and you’re looking at the recipe for a mammoth month.
So where is this sudden improvement in peripherals coming from? A change in strategy or mechanics? Well, it looks like the main source of the increased hard-contact is launch angle. In years past, Peralta wasn’t exactly a poster child for an ideal launch angle, consistently posting GB-rates greater than 50 percent. Now, he hasn’t really joined the infamous fly-ball revolution, but he is swinging the bat on a more ideal plane.
A 12-degree launch angle isn’t going to give you elite power numbers over a season, but it’s a major improvement on say a seven-degree one. He’s just avoiding the bad launch angles more.
To try and gauge this, I found the average wOBA on batted balls hit at or less than a zero-degree launch angle. As expected, it was low, standing at .164. I then found the percentage of batted balls that player hit at said launch angle. Lowering the minimum to 50 results, only 30 players out of 241 total hit at that range of launch angle more than David Peralta in that time. Performing the same exercise for just the single month of August, Peralta ranked 150th out of 247 batters in the negative launch angle-rate.
Looking on the flip side, I flipped the launch angle range to greater than 10 degrees (which has a league-average wOBA of .471). At this rate of launch angle range, Peralta ranked 299th out of 334 hitters with 50 results (beginning of the season to end of July). In the month of August, he’s been above-average, ranking 144th out of 328 hitters, minimum 10 results. Getting in a swing plane groove has Peralta turning in the best month of his career, crushing baseballs with the best of them this month.
August xwOBA Leaders
|Ronald Acuna Jr.||0.512|
One hot month is going to do the majority of the work in what should be a career year for David Peralta. A key cog in the Diamondbacks success- a team that’s fighting for an NL West title- they’ve been playing relatively good baseball the past month (only the Red Sox and Cardinals have had a better team wRC+ this month). If Peralta can continue at least some of this success, the Diamondbacks could be looking at a major boost in their postseason odds.
Patrick Brennan loves to research pitchers and minor leaguers with data. You can find additional work of his at Royals Review and Royals Farm Report. You can also find him on Twitter @paintingcorner.