Now may be a good time to mention that I advocated picking up Justin Bour back on May 1, although in a different column. Rather than simply calling him a waiver wire pickup or streamer, I'm going all in on the big man. Never let it be said that I'm not an unabashed fan of all Miami sports teams (even the Marlins). Hometown bias aside, I'll tell you why Bour, Altherr, and Rivero may ultimately be more valuable than Frazier, Desmond, and Hill.

Scouting players who may be undervalued and re-assessing players who may be overvalued is a weekly exercise that you should pursue. Fortunately, I have you covered. Here are a few players who are good buy or sell candidates based on their current performance compared to ownership levels. This could mean scooping them off waivers if possible or actively seeking a trade to acquire or discard certain players in order to maximize value.

I will include one player at each key position group (Infield, Outfield, Pitcher). Ownership levels are taken from Yahoo! Fantasy Sports.

Underrated Players - Week 10

Justin Bour (1B, MIA) 62% owned

You might be inundated with pleas to add Justin Bour off the waiver wire this week, but I'll take it a step further. Bour could legitimately finish as a top-10 first baseman in fantasy leagues this year. The only thing holding him back had been his outcomes against lefties. This season, he is actually hitting lefties better than righties (.343 vs .274) and isn't sitting out against LHP.

Those who think Marlins Park will suppress power are also wrong. They moved the fences in last year, moving the park up to 20th in HR Ballpark Factor for left-handed hitters so far this season. Bour has hit 10 of his homers at home, including another dinger on Friday night. Bour is now up to 16 HR, tied for the NL lead, along with 38 RBI with a .575 slugging percentage. If you've already added him as a streamer during this hot streak, consider holding pat for an extended period once he inevitably cools down.

Aaron Altherr (OF, PHI) 57% owned

He's slowed down since his torrid April, but Altherr has still been impressive. Consider that he's scored 25 runs and driven in 28 despite playing only 44 games for one of the worst offensive teams in baseball. He's slashing .291/.379/.534 and owns an impressive .243 ISO. Most of his numbers from 2016 can be overlooked because he was hurt in the first half and it appears his gimpy wrist affected his swing through the remainder of the season.

Projecting 20+ HR for Altherr might be hard considering he never even reached so much as 15 throughout the minors. In fact, Altherr has one of the lowest true distance averages for home runs this season among qualifiers. Don't add him expecting tremendous power, but at the rate he is getting on base and producing runs, he deserves a spot on way more fantasy rosters.

Felipe Rivero (RP, PIT) 30% owned

There's no guarantee Rivero will wind up saving games for Pittsburgh or any other team this season, but maybe he should. As closer Tony Watson has struggled to the tune of three blown saves and a 1.54 WHIP, Rivero has been lights out as a setup man. Rivero has allowed two earned runs over 27 2/3 innings of work and is striking out just over a batter per inning (26.9% K%). His WHIP sits at 0.83, mainly due to the fact he's inducing ground balls 64 percent of the time. Of the fly balls he allows, 22.2% never leave the infield. He uses a three-pitch combo to attack hitters and has seen a nice uptick in his fastball velocity, up to 97.7 MPH.

Even if he doesn't take over the closer role in Pittsburgh, he could be an attractive commodity elsewhere when the Pirates accept the fact they must be sellers at the deadline again. His former team, Washington, just might be in the market. In any case, fantasy owners should be too. If you're in a Holds or Sv+Hld league, he should have been owned a long time ago. If it's a league where you require four RP or have room to roster extra relievers, Rivero fits the bill as well. Finally, if you are just desperate for a closer and can't swing anything on the trade market, stash Rivero and hope he gets a chance to see the ninth inning on a regular basis in the second half.

Overrated Players - Week 10

Todd Frazier (1B/3B, CHW) 79% owned

We can't just keep blaming the BABIP here. Yes, Frazier did suffer from a league-low .236 BABIP last season and it's somehow gone even lower in 2017, down to .193. This may not be a simple case of bad luck, though. The last two seasons have seen Frazier's hard contact rate drop from 37.3% to 29.7%. Likewise, his soft contact rate is up to 22% and has actually risen for five straight seasons - every one since his rookie campaign!

Frazier is completely selling out for power, pulling the ball half the time and putting most of it in the air. When he's not hitting home runs, however, he's not hitting anything. If this approach were effective enough to get him double-digit homers by this point, you could make a case for holding onto him. At this moment, his horrific .184 average and pedestrian power numbers make him unplayable. At this point, Ryan Schimpf looks like a stronger play.

Ian Desmond (1B/OF, COL) 87% owned

The bad news is that despite an above average .358 BABIP and 33.3% Hard%, Desmond is only batting .270 with two homers and seven extra base hits in 122 plate appearances. He is yet to go deep in Coors Field either (so much for home-field advantage). The worse news is that he's only walking 2.5% of the time and has a wOBA of .287.

Those expecting another 20-steal season should also be disappointed to note that he has two steals compared to two times caught stealing. Desmond has five-category potential when it's all clicking, but he clearly hasn't gotten things going in Colorado. His fractured finger may still be bothering him, either physically or mentally. You won't get much value trying to sell him now, so he's best held on the bench until he shows signs of turning it around.

Rich Hill (SP, LAD) 85% owned

Where to start first, injuries or ineffectiveness? Hill has been on the shelf twice this year already for blisters and there's no guarantee it won't happen again. Eno Sarris of Fangraphs explained how his extreme curveball usage is likely to blame for the recurring problem. This season, he is relying on it more than ever, throwing it 53.5% of the time - the highest since 2012 and third highest of his career.

The velocity on his curve, just like his fastball, is down from last year. It's led to a lower swinging strike (8.2%) and a huge jump in fly ball rate (53.8%). Add in an alarming 5.73 BB/9 that has doubled from last season and it seems unlikely Hill will come close to replicating last year's success. He's only got five starts under his belt, so things could change quickly but I'm not willing to bet on it. There's a reason many fantasy owners like myself avoided Hill in drafts and now we're seeing it. By the second half, he find his way off many more fantasy rosters.

More Risers and Fallers

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