With nearly one-third of the 2017 NFL regular season complete, savvy fantasy football owners are looking for opportunities to buy low and sell high on potentially unsustainable performances. We spend the entire offseason predicting what will unfold once the action starts, but we can now finally use actual data and information to make decisions.

By detailing both negative and positive regression candidates, the hope is that we will uncover some of the truths behind what we've seen so far this year.

Negative Regression Candidates

Jared Goff, QB, Los Angeles Rams

It was bound to end sometime for second-year quarterback Jared Goff, wasn't it?

Regression struck hard against a very tough defense during a Week 5 loss to the Seattle Seahawks. Goff passed for 288 yards, no touchdowns (his first game this season without a passing score), and 2 interceptions. Per numberFire's schedule-adjusted metrics, the 'Hawks now rank second against the pass this season.

While Goff still ranks fourth in our Passing Net Expected Points (NEP) per drop back metric (0.24), his Week 6 matchup is even worse -- he takes on our top-ranked passing defense in the Jacksonville Jaguars. This is the same defense that just harassed Big Ben Roethlisberger into five interceptions last week.

Goff has slid all the way down from a top-end quarterback to QB14 and he could be sliding further soon.

Frank Gore, RB, Indianapolis Colts

We are going to talk about the other side of this equation soon, but let's discuss the production of Frank Gore and why he could slide back even further.

Among the 44 running backs that have toted the rock 30-plus times, Gore ranks 33rd (-0.14) in Rushing NEP per carry. It doesn't get any better after peeping his Success Rate -- the percentage of plays that result in positive NEP -- as he ranks 43rd of that same group with a 29.33% rate. Only Paul Perkins is worse than Gore when looking at this metric. Woof.

While he did recored three receptions, Gore gained just 48 yards on 14 carries. A changing of the guard may be occurring rather quickly.

Jordy Nelson, WR, Green Bay Packers

Many of you thought I was crazy (and told me as much on Twitter) for listing Jordy Nelson here last week. He did hit paydirt, but was held to 2 catches for only 24 yards.

Here's the good news -- Nelson is still an extremely efficient player. He's the WR6 in half-point PPR leagues, and in looking at Reception NEP per target, his 1.08 mark leads all receivers with at least 25 targets. That's the good.

The really bad is that he will square off head-to-head with cover monster Xavier Rhodes in Week 6, who added to his dominance by adding another victim to his list last week. Rhodes has yet to allow a receiver to break 70 yards receiving in 2017, and he's fresh off allowing a passer rating of only 47.0 against him last season.

Coby Fleener, TE, New Orleans Saints

It's not you, Coby Fleener, it's me, and I am officially cutting bait.

When Fleener hit the jackpot and signed a five-year contract with the New Orleans Saints, it felt like the sky was the limit in this passing offense. But after decent results in 2016 -- 50 catches for 631 yards -- things are looking a little different in 2017.

The Saints are still chucking the ball a ton -- they have the seventh-highest mark in football with regard to pass-to-run ratio (1.68) -- so the volume is there for success. And while Fleener has caught two touchdowns this year, they happened in Weeks 1 and 2. He's been virtually non-existent since then.

In Weeks 3 and 4, Fleener recorded only three catches on five targets, which is only only two more targets than backup tight end Michael Hoomanawanui. Fleener now ranks fifth on the team in targets, snagging a 10.0% target market share among Drew Brees' 152 drop backs this year.

Unless he suddenly reasserts himself in this offense, Fleener is about to tumble his way into irrelevance at the tight end position.

Positive Regression Candidates

Cam Newton, QB, Carolina Panthers

It turns out Superman lives after all. Cam Newton has exploded the last two weeks to the tune of 671 passing yards and 6 touchdowns after a sluggish start.

But what may accelerate Cam's rise up the quarterback ranks even further is his 15 rushing attempts over the last two weeks, which included a score in a Week 4 win over the New England Patriots.

Among the 32 quarterbacks with 100 drop backs or more, Cam has been very solid, ranking fifth (0.23) in Passing NEP per drop back. He could join the elite fantasy ranks soon and climb up from his current QB8 ranking very soon.

Marlon Mack, RB, Indianapolis Colts

Get yourself some, young fella'. It could be Marlon Mack time in Indianapolis.

After a shoulder injury held him out of consecutive games, Mack exploded in Week 5 with 9 carries for 91 yards and a score. While he's seen limited playing time this, he's been pretty effective. Among 70 running backs with 15 carries or more, Mack ranks 24th in Rushing NEP per carry (-0.01) in 2017.

It may just be a one-week blip, but Mack looked pretty darn good. If he continues to steal snaps and carries from Frank Gore, he could rise up quickly from his current rank of RB45.

Aaron Jones, RB, Green Bay Packers

The darling of Week 5 is officially breaking the numberFire database.

Aaron Jones grabbed the start with Ty Montgomery sitting out due to a rib injury, and Jones crushed to the tune of 20 touches for 134 total yards and a score. While there was some debate over whether he or Jamaal Williams would get the lion's share of playing time, Williams only saw a single carry.

Jones currently ranks as the RB39, but given last week's efficient performance -- which has helped him produce a Success Rate of 59.38% for the year -- he won't stay there for very long if he continues getting opportunities.

T.Y. Hilton, WR, Indianapolis Colts

Sitting just outside of the top 10 wide receivers, T.Y. Hilton seems poised to join that group very soon.

The Indianapolis Colts wideout has put together two monster games in three weeks, notching 7 catches for 153 yards and a score in Week 3 before catching another 7 passes for 177 yards in Week 5. This is also coming at a high level of efficiency -- Hilton currently ranks fifth in Reception NEP per target (0.94) this year.

It'll get even better for him in Week 6, as he's set to face a Tennessee Titans pass defense that ranks 29th per our metrics. It's worth noting they've already allowed monster efforts from DeAndre Hopkins (10 catches for 107 yards and a touchdown) and Doug Baldwin (10 catches for 105 yards and a touchdown).