RotoBaller's Nick Mariano looks at some fantasy baseball bats for week eighteen that are hitting 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 and Aaron Judge are strong or that Jarrod Dyson and Billy Hamilton are toward the bottom in average exit velocity. We're now in the final third of the fantasy baseball season with only a shade over a week from the traditional mid-August trade deadline for many leagues.

Identifying top power risers and fallers for each week can help you swing the best deals and spot the best pickups before your competition. We'll do the hard work for you, looking at the underlying metrics that influence a hitter's power: fly-ball, pull, hard-hit rates and exit velocity. Consider buying these week 18 power risers and selling these week 18 power fallers.

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Power Risers

Maikel Franco - (PHI, 3B):

This is going to surprise some folks, and by that, I mean anyone who can read Franco’s stat line. He’s gone just 8-for-50 over his past two weeks heading into Thursday night, but at least two of those eight hits left the park. His fly-ball rate is sitting near 50 percent and his pull rate is a shade north of 60 percent, but a lowly 22.6 percent hard-hit rate and nonexistent 6.5 percent line-drive rate have continued to hold him back. Still, two out of three key power metrics are trending upward and if he starts getting his timing down with a lifting swing, look out. At this point in the season, taking him on should come with a bargain-bin price tag.

Gerardo Parra - (COL, 1B/OF):

Since the last few days in May, Parra has been verifiably on fire. There was a lengthy injury sprinkled in of course, so it isn’t like he’s been dominant over the past two-plus months, but in 114 plate appearances he’s triple slashing .466/.474/.709 with a .484 BABIP. Sustainability jokes aside, his last two weeks have seen him post a modest fly-ball rate of 31 percent with a 40 percent pull rate and 44 percent hard-hit rate. While the right-field wall is high in Coors Field, a guy who is locked in like this is set to continue producing down the stretch in the regular season’s final two months. It only helps that his line has been strong to-date, but many don’t trust this to hold up in the least and one sight of his BABIP usually leaves owners more than willing to flip him.

Edwin Encarnacion - (CLE, 1B):

Encarnacion has gone 11-for-43 (.256) over the last two weeks, as he actually has more walks (12) than hits. His power hasn’t disappeared -- three doubles and three homers populate his game log over this span -- but we’re talking about a guy who historically hits very well in the summer (well, any time later than April) and has a fly-ball rate of 40.6 percent, hard-hit rate of 46.9 percent and a pull rate of 62.5 percent. Considering his .213 batting average since the All-Star break and his slow start to the season, fantasy owners might be able to grab the bat that produced an .870 OPS and .257 ISO in the second half of 2016 with at a discount.

J.T. Realmuto - (MIA, C):

And just like that, Realmuto has eclipsed his homer tally from 2016 in 174 fewer plate appearances. While he’s on pace to fall short of his 12-steal mark from ’16, his ISO jumping from .126 to .178 has more than made up for it. It might be difficult to pry the Marlin from his owner, but he’s pulling the ball over half of the time (58.8 percent) with a 41.2 percent fly-ball rate and 44.1 percent hard-hit rate.

Unlike many other big swingers, his 20 percent line-drive rate in that window shows that he hasn’t totally sold out for an uppercut and still has his comfortable .300-average swing behind the muscle. Interestingly enough, he’s hitting just .243 on four-seam fastballs compared to .352 last season, but his average and slugging percentage has soared against nearly all forms of the breaking ball. Realmuto has an average greater than .300 and a slugging percentage over .500 against sliders, changeups and curveballs, so I believe he may really be coming into his own down the stretch in Year Two.

Power Fallers

Francisco Lindor - (CLE, SS):

Whaaaat? Lindor, a seller? He’s on a 13-game hitting streak in which he’s socked four homers, making for the perfect springboard to sell high if someone wants to unload him. Over that hitting streak, his 25.6 percent soft-contact rate actually outpaces his 23.3 percent hard-hit rate. He’s hitting more grounders (42.5 percent) than fly balls (32.5 percent) and he’s spraying the ball up the middle (35 percent) and the opposite way (39.5 percent) more than he’s pulling the ball (25.5 percent). This HR/FB rate over 25 percent feels like a bit of sham, though this is in no way saying that Lindor is bad or that his batting average isn’t deserved. This is still a guy with solid pop and decent speed from the shortstop position, but perhaps people are envisioning that guy who blew up in April coming back to life here when the metrics just aren’t supporting it.

Corey Dickerson - (TB, OF):

So Dickerson has notched multi-hit games in three of his last four games and is hitting .264 with four homers over his last two weeks of play. Given how well he did in the first two months of the season, this little spurt could be seen by many as a return to form for the 28-year-old. The only thing is, while his 40 percent fly-ball rate and 56 percent pull rate are very healthy, his 21.9 percent hard-hit rate is contributing very little to the cause. The difference between he and Franco is that Franco is coming from the bottom and Dickerson is trending downward but still has value on the season. He’s showing a little life right now with the pop, but his struggles in July (.220 average, no homers before the All-Star break) are simply being masked over. It’s not looking good.

Miguel Sano - (MIN, 1B/3B/OF):

Sano’s 10-for-45 stretch with two homers and 20 strikeouts over the last two weeks has come with a mild 27 percent fly-ball rate, 41 percent pull rate and 36 percent hard-hit rate. For anyone not named Miguel Sano -- one of the league leaders in exit velocity and barrels -- these numbers might be okay, but a hit to his almighty swing means his “three true outcomes” process is severely weakened.

The 24-year-old’s 35 percent strikeout rate remains absurd, but he’s hit between 5-7 homers in each month thus far with steady counting-stat contributions. The thing is, his ISO dipping from .262 across the first half to .200 in the second half (17 games) reflects his rolling average exit velocity falling below 90 mph recently. Simply put, that’s nothing special. There are plenty of Sano purists out there who will pay for his ceiling.

Carlos Gonzalez - (COL, OF):

CarGo may have seen his 11-game hitting streak come to end on Thursday, but let’s look at that streak just to see what it really holds. First of all, he hit three doubles and a homer within that stretch for his only extra-base hits against 10 singles. Second of all, his fly-ball and pull rates are hovering around 26 percent with a hard-hit rate at 28.6 percent. Yup, none of those marks exceeding 30 percent is a problem. The hitting streak may have lulled some folks into feeling like he’s turned a corner here and that a breakout is inevitable, but this just doesn’t look to be the case. His reputation, the streak and his second-half explosion from two years ago might be enough to get a decent piece in return here.

More Risers and Fallers