Regression is a big deal in fantasy football.

Who doesn't want to get in low on a player whose peripheral data is better than his fantasy point tallies are? Who wouldn't want to trade away a player who is playing way above expectation -- or perhaps avoid him in daily fantasy formats?

Expected regression is something that we can apply both to season-long fantasy football but also daily fantasy, as well.

So, I went through and paired up various parts of our Matt Ryan and Philip Rivers continue to stick out as huge outliers, and each are at least 29.8 points from their expected totals based on their underlying passing metrics. Ryan's per-drop back Passing NEP of 0.20 and Rivers' of 0.25 are well above the NFL average of 0.13. There's a lack of rushing from each of these guys, but they are each 6.3 expected passing touchdowns below expectation based on their efficiency and volume.

Daniel Jones (23.9 fantasy points below expectation) and Teddy Bridgewater (19.5) are next in line. Jones hasn't been good (0.00 Passing NEP per drop back) but should be at 13.3 touchdowns yet has only 8. Bridgewater should be at 20.1 but has thrown for just 14.

Believe it or not, Patrick Mahomes is 10.5 fantasy points below expectation, which is a slim margin at this point in the season, but his production is very much legitimate, unlike a few other top-tier quarterbacks through Week 12.

Negative Regression Candidates
Four quarterbacks are at least 30 fantasy points over expectation: Carson Wentz (37.3), Russell Wilson (33.6), Tom Brady (32.2), and Taysom Hill (32.2). Why? Well, the first three are all top-five in passing touchdowns over expectation (Wilson [8.0], Wentz [5.0], and Brady [4.2]).

Wilson's touchdown rate (passing touchdowns per drop back in this instance) is 7.2% but should be 5.4%, based on his Passing NEP per drop back (0.23). He's actually been less efficient than Rivers (0.25) once you factor in his interceptions and 35 sacks (for a loss of 54.6 NEP). Wentz has a Passing NEP per drop back of -0.12, the lowest mark of all 24 quarterbacks with at least 300 drop backs.

Hill, obviously, is really boosted from his short-yardage rushing touchdowns and minimal passing work. He should have about 20.7 rushing fantasy points instead of his 58.1. Stealing goal-line work won't increase expected scoring much (because he's not the one moving the ball down the field) but does lead to a ton of fantasy points.

Running Backs

Positive Regression Candidates
Fantasy points are pretty easy to predict among running backs because volume -- not efficiency -- generally leads to production and especially touchdowns.

That's why Frank Gore remains a positive regression candidate. He should have about 21 more fantasy points than he has, mostly through 3.5 more touchdowns. Kerryon Johnson (-18.3) would be a name to monitor if D'Andre Swift were to be hurt again. Losing goal-line work to Adrian Peterson is a problem, though.

Other notable names near the top are Kareem Hunt (-15.0), Latavius Murray (-14.8), and Austin Ekeler (-14.8).

Negative Regression Candidates
Antonio Gibson (58.6 fantasy points over expectation) is a scary addition to the list. He has scored 4.6 total touchdowns above his expected output. If he regresses to the mean in that department, we could see a cold stretch for the hot-running rookie.

Ronald Jones (42.2 fantasy points over expectation) and Dalvin Cook (41.5) have gotten there in different ways. Jones has relied on long plays (which aren't super bankable) but is actually 1.4 touchdowns under expectation. His receiving work has been largely empty from a NEP standpoint, so he's over-performing in that department. Cook is 3.7 touchdowns above expectation because he's so involved in the red zone.

Melvin Gordon is 38.5 fantasy points over expectation by way of 2.1 touchdowns over expected. The bigger explanation is that he's been a horribly inefficient receiver, similar to Jones.

Wide Receivers

Positive Regression Candidates
This section of the regression list isn't as eye-opening as the negative regression list at receiver, but D.J. Moore (18.5 fantasy points below expectation) is the position leader and is 2.2 touchdowns below where he should be. It makes some sense that his quarterback, Bridgewater, is underachieving there as well.

Touchdown issues plague most of the next-closest under-performers. Tyler Boyd (18.2 fantasy points below expectation) has 3 touchdowns but should have 5.6, Jarvis Landry (17.1) has 1 touchdown but should have 4.1, Danny Amendola (16.9) hasn't scored yet but should have 2.7 based on his production), Damiere Byrd (15.7) has 1 touchdown but should have 3.4, and Julio Jones (15.5) has 3 touchdowns but should have 4.8.

Negative Regression Candidates
Some big names again land toward the top of the list at receiver. Robert Woods (32.9 fantasy points over expectation), Davante Adams (27.3), Adam Thielen (26.1), CeeDee Lamb (22.6), and Allen Robinson (19.3) are the top five.

Is it all touchdown-based? Kinda sorta -- at least for Woods (1.4 touchdowns above expectation), Adams (4.5), and Thielen (6.0). Lamb and Robinson are within half a score of expectation.

Only Thielen (6.0) and Mike Evans (5.9) are at least 5.0 touchdowns above expectation. Those close behind are Tyreek Hill (4.9), Adams (4.5), Chase Claypool (3.9), and A.J. Brown (3.2).