American League: Khris Davis, Andrew Benintendi, Shin-Soo Choo
National League: Jay Bruce, Scott Schebler, Andrew McCutchen
We all know about Khris Davis' immense power, with 24 bombs already this year, due in no small part to a 44.2% hard-hit rate and 42.2% fly-ball rate. Although his strikeout rate is even higher than usual (31.8%), an improved walk rate (11.7%) has him at his highest OBP since his rookie season (.334). While some may dismiss him as another flawed Chris Carter-type who punches out too much, a .385 xwOBA says otherwise.
Andrew Benintendi went through a bit of a rough patch in May, but since the start of June he has a stellar 44.2% hard-hit rate and 46.2% fly-ball rate. Difficult to strike out (15.8% rate) and with speed to boot (nine stolen bases), Benintendi has a little bit of everything going on. Arguably the most hyped prospect entering the season, now that he's survived his first hurdle, he might be ready to take the next step.
Our final AL nod goes to the always underappreciated Shin-Soo Choo, who actually made this very same list last year. He may not blow you away with the power of some of the previous names, but with a 37.7% hard-hit rate and 14.2% walk rate, he's up to his usual OBP tricks (.363). Still, 12 dingers isn't too shabby, and he can still swipe a bag at the age of 34, with seven stolen bases. He lacks the flash and hype, but a .375 xwOBA highlights how valuable he is this season.
After getting shopped around during the offseason, the New York Mets somewhat reluctantly kept Jay Bruce, and, what do you know, he's turned into one of the few bright spots for the team, sporting a 42.9% hard-hit rate and 48.8% fly-ball rate. He already has 23 homers, and so far his .272 ISO is the highest of his career. As long as he's hitting fly balls with this kind of regularity, there's no reason he can't exceed last season's 33 long balls.
Not many expected big things from Scott Schebler in 2017, but 22 home runs later, people have begun to take notice. He's got that 40.6% hard-hit rate in his holster, and now that he's pushed the ground-ball rate below 50%, it's translating to the power he hinted at in the minors. With a .375 xwOBA, we could have a real breakout on our hands.
Last but not least, let's acknowledge another "old" hand in Andrew McCutchen. Left for dead, then back, then left for dead again, McCutchen might be the equivalent of the baseball walking dead given the number of times he's been written off since last season. Following a prolonged slump over the first couple months, since the beginning of June he's slugged nine bombs, and maintained a 37.4% hard-hit rate and ridiculous .438 xwOBA. It's easy to forget he's still just 30 years old, and he's striking out at his lowest rate since 2013 (16.3%). While at this point we may have to acknowledge that extended slumps are just part of the deal, it's time we have a little more faith in McCutchen moving forward.