May offense: wRC+ leaders at each position

Before we close the book on May, let's look back at the best offensive players at each positions according to weighted runs created plus (wRC+), 'a rate statistic that weights each offensive action and controls for league and park effects.' To qualify as a leader, each player must have played at least 50 percent of their games at the position, though as you'll soon see, I subscribe to the philosophy of making rules simply to break them.

Catcher: Stephen Vogt (178)

At the risk of spoiling what is to come, Oakland A's catcher Stephen Vogt is the only holdover from the April list of wRC+ leaders at each position. Vogt hit a whopping 7 HR in May. That's as many as teammate Josh Reddick -- who is second on the team in HRs -- has hit all season, and 25 percent of his team's 28 May HRs. All the while, he has continued to exhibit excellent plate discipline, striking out as often as he walked (16). In early May, Eno Sarris wrote that he was a Vogt believer, relaying that the key to the backstops success has been swinging with greater effort, rather than guiding the bat through the zone and making more frequent, but weaker contact. No word on whether or Vogt also sang Eno a lil' Sass Jordan for good measure.

Honorable mentions: Francisco Cervelli (165), Buster Posey (161)

First Base: Paul Goldschmidt (219)

Adrian Gonzalez was the offensive leader at first base in April, but Goldschmidt was an honorable mention with a wRC+ of 183 in the first month. In May, he doubled his April output with 10 HR while also tying Bryce Harper and Adam LaRoche for most walks (22), 9 of which were intentional. That led the league by a wide margin, as only Miguel Cabrera (6) had more than 4 IBB. Goldschmidt is now second among qualified batters for wRC+ on the season and is putting together a campaign that is quietly challenging Harper for best in the senior circuit.

Honorable mentions: Brandon Belt (198), Anthony Rizzo (181)

Second Base: Jason Kipnis (241)

Jason Kipnis followed up a dreadful April with one of the best May totals of all time. Here's a quick rundown of the categories in which he led the league:

• Hits (51)
• Runs (30)
• Total bases (84)
• Doubles (15)
• Triples (3) (tied with honorable mention Brian Dozier, Marcus Semien, and Jean Segura)
• Plate appearances (143) (eight more than Prince Fielder and Shin-Soo Choo)

Pretty good.

Honorable mentions: Brian Dozier (170), Joe Panik (160)

Shortstop: Jhonny Peralta (160)

Like so many other wRC+ leaders, Peralta also led his position in HR (6) and ISO (.250) in May. What's notable about Peralta is that at 33 he's the oldest player to lead his position at wRC+ this month. Not notable enough? How about hitting 5 of his 6 May HRs at home?

How about not hitting a single HR when his team had the lead?

Well, how about hitting the third-longest HR at PNC Park this season (436 ft)?

Well I'm sorry but that's going to have to do.

Honorable mentions: Brandon Crawford (158), Jung-ho Kang (140)

Third Base: Todd Frazier (194)

Now this one was a surprise. I would have bet a lot of money that after the month Josh Donaldson had that I'd be writing about his accolades under this heading. That was not to be as Frazier bested out the his profane peer. Donaldson had one more HR, hit, and double than Frazier to lead third basemen, but Frazier logged 14 fewer PA which gave him the advantage in the rate stats for these categories. So why do they call him the Toddfather? Well, judging by Bryan Price's tyrade on C. Trent Rosencrans earlier this year, I'm guessing it wasn't by speaking to his boss like this:

Honorable mentions: Josh Donaldson (178). Trevor Plouffe (163)

Right Field: Bryce Harper (264)

Bryce Harper. What to say, what to say? After launching 3 consecutive bombs off Tom Koehler on May 6th, it seemed that Bryce Harper had turned the corner, and become the feared slugger we'd been dreaming off since he graced the cover of SI at 16. His third shot that day was a majestic 441-foot blast. Koehler's reaction is pretty priceless too. That is the body language of a man who who has resigned himself to his role in highlight clips.

His 13 round-trippers were the most in a month since month since May of last year when Edwin Encarnation (16) and Nelson Cruz (13) went off. So far this season, only 6 players have more HR than Harper had in May alone. Of course, not all of his HRs were no-doubters. Take his 12th of the month when Harper exhibits all the classic signs of disgust on what he thought was a flyball out, only to have the Windy City's namesake carry the ball over the left field fence. Good thing Madison Bumgarner wasn't on the mound...

Oh, and his ISO (.523) was .138 greater than the next highest (Paul Goldschmidt). That difference is the same ISO as Matt Kemp, Robinson Cano and Adam Jones in May--combined. If you're reading this site, it's probably for cherry-picked data just like that.

Honorable mentions: Nelson Cruz (186), Chris Colabello (176)

Center Field: Andrew McCutchen (172)

Like Kipnis, McCutchen had a rough April, possibly due to knee issues he'd been battling since spring training. He managed to shake it off in May, leading his position in wRC+ by a pretty wide margin. McCuctchen didn't do it by dominating any one category, but rather ranking among the best center fielders in hits (35, 2nd), double (10, 1st), HR (5, t3rd), and walks (16, 4th). Oh, and he was pretty nice to some youngsters who will clearly be 'Cutch fans for life.

Honorable mentions: Joc Pederson (139), A.J. Pollock (136)

Left Field: Justin Upton (171)

New city, same old Justin Upton. The Padres left fielder tore the cover off the ball in May, leading left fielders in wRC+. But I'm going to break my arbitrary rules here because Toronto Blue outfielder Chris Colabello would have led LF (176) had he not played 5 more innings in RF where he was an honorable mention behind Harper.

With the Twins, Colabello was the definition of a quad-A player. Now, for a 31 year-old who toiled 7 season in independent ball, that's a pretty high praise. In 2012, he slugged 19 HR across 561 AA plate appearances. He started off 2013 in AAA and would hit 24 bombs at that level (391 PA) between call-ups to the Twin Cities. In 791 AAA PAs he's hit 39 bombs, but in his 401 PA for the Twins he hit 13 while striking out over thirty percent of the time. Colabello has only seen action for the Jays since May 5th but he's managed to trim his strike out rate to a more respectable 25 percent while BABIPing (.477) his way to a .368 batting average. There is absolutely no way this lasts, but Jays fans shouldn't let my cynicism diminish their joy in watching his late-in-life success. They'd probably remind me that he's just now succeeding because he's finally healthy. After seeing Jose Bautista and Edwin Encarnacion blossom under the dome, who can blame them?

Honorable mentions: Marlon Byrd (152), Michael Brantley (140)

Designated Hitter: Prince Fielder (198)

I'm sure that some Ranger fans have delighted at Kinsler's struggles in Detroit this season. He's managed only 1 HR in 226 PA. Some of the more exuberant Fielder supporters may have even declared that trade a win for the Jon Daniels. While Fielder's lost season will be difficult to make up for, he did his level best in May, slugging 9 of Texas' league leading 42 HRs.  With each HR, Prince (298) draws closer to surpassing his father Cecil's MLB career total of 319.

Honorable mentions: Alex Rodriguez (157), Jose Bautista (156)

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Matt Jackson is a featured writer for Beyond the Box Score and a staff writer for Royals Review. You can follow him on Twitter at @jacksontaigu.