RotoBaller's Nick Mariano looks at some fantasy baseball bats for week eight that approach the end of May either extremely hot or cold in the power department.

Welcome back to this investigative piece where we examine players who have seen some notable changes in their power profiles -- for better or for worse -- in 2017.

As usual, you don’t need me to tell you that Miguel Sano or Aaron Judge are strong or that Jarrod Dyson and Billy Hamilton are toward the bottom in average exit velocity. We're nearing the two-month mark on the 2017 season and it's safe to say that sanity is nowhere in sight. Let's see if we still can't give some context to some surging bats with regards to power using our trusty little RotoBaller premium toolbox.

For reference, here's a tasty little screencap of the premium power tool that much of the inspiration for this article comes from. It pulls the fly-ball, pull and hard-hit rates for players -- metrics associated with power -- and looks at notable recent swings in performance.

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Power Risers and Fallers - Premium Tool

Identifying top power risers and fallers for each week can help you spot the best pickups before your competition. RotoBaller's Premium Power Risers and Fallers tool has you covered every day. Here's a free sample:

Power Risers

Justin Bour - (1B, MIA):

Bour owns a ridiculous .535 ISO over the last two weeks with eight homers over his last 12 starts, so yeah, we’re going to have to speak on this. And he hasn’t just been hitting long balls, going 19-for-46 (.413) overall with a ridiculous 60 percent hard-hit rate and identical pull rate while hitting the ball into the air at a 40-percent clip.

The 28-year-old has 12 homers overall in just 175 plate appearances after leaving the yard 15 times in 321 PAs last season, though his current 32.4 percent HR/FB rate will tumble toward 20 percent. However, the biggest part of this is that he’s gone 10-for-33 with his first three career homers against southpaws in 2017. He had hit just .223 over his first 103 at-bats vs. LHP, so this improvement should lead to true full-time play and 30-homer potential.

Michael Conforto - (OF, NYM): 

While Conforto had an ugly four-strikeout game the day of my writing this, his prior six games had yielded two doubles, four homers, 10 runs scored and eight RBI alongside an insane .476 average. He only hit five fly balls in total, but four of them left the park thanks to a 71.4 percent hard-hit rate in those games.

10 of his last 12 batted balls checked in at 97-plus mph, with only one of those carrying a negative launch angle. Even including the previous week for a two-week window, he has a robust 65.5 percent hard-hit rate and a paltry 6.9 percent soft-contact rate alongside a 48.3 percent fly-ball rate. Hopefully, the return of Yoenis Cespedes doesn’t dig into Conforto’s breakout. It shouldn’t, but my trust in Terry Collins is nil.

Alex Bregman - (3B, HOU):

While it hasn’t been the flashiest showing, Bregman’s first three homers of the season have come over his last 10 starts. The sophomore has posted a solid 34.5 percent hard-hit rate (30.9 percent otherwise), but the 44.8 percent fly-ball rate (33.3 percent) and 55.2 percent pull rate (34 percent) illustrate a change in approach. What was really terrible was his 21.9 percent infield-fly rate, which has been cut to 7.7 percent in his last two weeks.

Now, the caveat with his three homers is that one of them went 348 feet while another went 349 feet. He does have a 402-foot field out to his name as well, but honestly, this is more about making sure people aren’t getting too excited about the recent “homer” surge. The signs are there

Mike Napoli - (1B, TEX):

Napoli’s 19 barrels are tied for the seventh most in the MLB, which has translated to 11 homers overall and six long balls (though just 11 RBI) over his last two weeks. His fly-ball and pull rate both sit at 55.6 percent in that span, with an impressive 48.2 percent hard-hit rate making those pulled flies useful. He's 12-for-41 (.324) in that two-week window, so half of those hits have migrated to Souvenir City and 16 of his 29 outs have come via strikeout. Napoli isn't new to the "swing for the fences" approach -- he hit 34 homers with a 30.1 percent strikeout rate in 2016 -- but his soft-contact rate has risen by five percent compared to last season. Again, it won't matter much as long as his loud contact is counting for something, but it does explain some of his atrocious .212 BABIP (.296 in '16) and subsequent .193 batting average. That's difficult to stomach even if you reach the 35-homer, 100-RBI plateau.

Power Fallers

Carlos Correa - (SS, HOU):

Correa just returned from a brief illness and homered, so that kind of takes away from the message at-large here. That said, I'm stubborn and already penciled him into the lineup, and also it doesn’t change that he had smacked only one ball over 350 feet over the past two weeks before Thursday night. There’s no skirting that judging 40 plate appearances is harsh, but an 18.2 percent hard-hit rate is going to give you troubles when courting the home run. That and half of the balls he hit were grounders. And he only pulled 13.6 percent of them. I highly doubt anyone would "sell low" on him, but there might be some people selling him off for 90 cents on the dollar given the ebbs and flows with power and the fact that he hasn't attempted a steal yet (it isn't all about power, after all).

Dustin Pedroia - (2B, BOS):

Pedroia lost his six-game hitting streak on Thursday and was removed for precautionary reasons with left knee soreness. The 33-year-old went from logging an extra-base hit in eight of nine games from May 4-13, but in 10 games since then he’s only mustered one (a double). He's still hit .293 since then so the average isn't ailing and he's only been rung up three times in the 41 at-bats since, but there's just no zing, no pep. It isn't as though he was drafted for homers, but the guy did hit 15 dingers last season and is currently rocking a 4.5 percent HR/FB rate that would be his worst since his first full season in 2007 (4.4 percent).

He's definitely earned the struggles, with just a quarter of his batted balls going in the air with a puny 8.3 percent hard-hit rate backing it. Throw in a 16.7 percent pull rate and you've got an ugly power picture. The interesting thing here is that you could easily say he's not a "faller", but rather has been down all season. He's one of seven players with at least 50 batted balls who have yet to register a "barrel" on a hit. If you can get something for him on name value alone, I'd go for it.

Marcell Ozuna - (OF, MIA):

Ozuna hasn’t gone yard since his two-homer game on May 8, with only three doubles in 14 games since then. Granted, he’s hit safely in nine of his last 11 games, but we want the powah! So since then, he’s put up a ghastly 56.4 percent ground-ball rate alongside a 30.8 percent hard-contact mark, which is below league-average. Oh.

In case you’re wondering, that’s not good when it comes to power. His hard-hit rate was 49.4 percent before the power outage hit, and while his primary outcome was still the grounder, they only came at a 44.9 percent clip. Mix in an 11-percent drop in his pull rate and viola, you’ve got a candidate for this article. While he should rebound from this slump, the fact that he hasn’t even hit a ball more than 285 feet in a week is alarming.

Giancarlo Stanton - (OF, MIA):

The outfield that slumps together, stays together? At least Bour's safe in the infield. Like his teammate Ozuna, Stanton also hasn’t been able to clear the fence since May 8, though he has six doubles since then so there’s that. While he’s still slapping the souls out of baseballs with his swing (six balls hit at 112 mph or greater in the past week), none of them have been at a launch angle greater than 15 degrees. That points to a poor 23.8 percent fly-ball rate since May 8 and explains the laser-beam doubles not turning into homers. This seems like a rather easy fix at first glance -- especially given his 22 percent strikeout rate since May 8 is below his season-long mark of 24.2 percent -- but being a bit on top of the ball certainly presents a legitimate hurdle no matter how you slice it.

More Risers and Fallers

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