Welcome to Regression Alert, your weekly guide to using regression to predict the future with uncanny accuracy.

For those who are new to the feature, here's the deal: every week, I dive into the topic of regression to the mean. Sometimes I'll explain what it really is, why you hear so much about it, and how you can harness its power for yourself. Sometimes I'll give some practical examples of regression at work.

In weeks where I'm giving practical examples, I will select a metric to focus on. I'll rank all players in the league according to that metric and separate the top players into Group A and the bottom players into Group B. I will verify that the players in Group A have outscored the players in Group B to that point in the season. And then I will predict that, by the magic of regression, Group B will outscore Group A going forward.

Crucially, I don't get to pick my samples (other than choosing which metric to focus on). If I'm looking at receivers and Cooper Kupp is one of the top performers in my sample, then Cooper Kupp goes into Group A and may the fantasy gods show mercy on my predictions.

Most importantly, because predictions mean nothing without accountability, I track the results of my predictions over the course of the season and highlight when they prove correct and also when they prove incorrect. At the end of last season, I provided a recap of the first half-decade of Regression Alert's predictions. The executive summary is we have a 32-7 lifetime record, which is an 82% success rate.

If you want even more details, here's a list of my predictions from 2020 and their final results. Here's the same list from 2019 and their final results, here's the list from 2018, and here's the list from 2017.

The Scorecard

In Week 2, I broke down what regression to the mean really is, what causes it, how we can benefit from it, and what the guiding philosophy of this column would be. No specific prediction was made.

In Week 3, I dove into the reasons why yards per carry is almost entirely noise, shared some research to that effect, and predicted that the sample of backs with lots of carries but a poor per-carry average would outrush the sample with fewer carries but more yards per carry.

In Week 4, I discussed the tendency for touchdowns to follow yards and predicted that players scoring a disproportionately high or low amount relative to their yardage total would see significant regression going forward.

In Week 5, I revisited an old finding that preseason ADP tells us as much about rest-of-year outcomes as fantasy production to date does, even a quarter of the way through a new season. No specific prediction was made.

In Week 6, I explained the concept of "face validity" and taught the "leaderboard test", my favorite quick-and-dirty way to tell how much a statistic is likely to regress. No specific prediction was made.

In Week 7, I talked about trends in average margin of victory and tried my hand at applying the concepts of regression to a statistic I'd never considered before, predicting that teams would win games by an average of between 9.0 and 10.5 points per game.

In Week 8, I lamented that interceptions weren't a bigger deal in fantasy football, given that they're a tremendously good regression target, and then I predicted interceptions would regress.

In Week 9, I explained why the single greatest weapon for regression to the mean is large sample sizes. For individual players, individual games, or individual weeks, regression might only be a 55/45 bet, but if you aggregate enough of those bets, it becomes a statistical certainty. No specific prediction was made.

In Week 10, I explored the link between regression and luck, noting that the more something was dependent on luck, the more it would regress, and predicted that "schedule luck" in the Scott Fish Bowl would therefore regress completely going forward.

In Week 11, I broke down the very important distinction between "mean reversion" (the tendency of players to perform around their "true talent level" going forward, regardless of how they have performed to date) and "gambler's fallacy" (the idea that overperformers or underperformers are "due" for a correction).

In Week 12, I talked about how much of a team's identity was really just random noise and small samples and projected that some of the most rush-heavy teams would skew substantially more pass-heavy going forward.

In Week 13, explained why the optimal "hit rate" isn't anywhere close to 100% and suggested that fantasy players should be willing to press even marginal edges if they want to win in the long run.

In Week 14, I sympathized with how tempting it is to assume that players on a hot streak can maintain that level of play but discussed how larger (full-season) samples were almost always more accurate. I predicted that the hottest players in fantasy would all cool down substantially toward their full-season averages.

In Week 15, I discussed several methods of estimating your championship odds and explained why virtually every team is more likely to lose than to win.

In Week 16, I examined what happened to some of our failed predictions if you looked at them over longer timespans and found that while regression could be deferred, the bill eventually came due.

Regression and Dr. Ian Malcolm

My first love in fantasy football is dynasty, a format where once players are on your roster you keep them indefinitely, drafting new rookies every year as a fresh batch of players enters the league. This column naturally focuses on shorter time scales with predictions that are testable over four-week windows, but late in the season, I like to deviate a bit and look at a way that regression impacts my favorite format. By now, the redraft cake has already been baked, so to speak; 80+% of teams are already eliminated from contention and the ones that are still alive don't have much of a future to look forward to. But dynasty is forever.

In recent years, I've taken the opportunity to look at how incoming talent tended to regress over time, with positions getting younger once a strong crop of rookies entered the league and then older over time as that group aged. The 2017 running back class was the best in history, so top running backs were very young after 2017 and 2018 but much older today as Christian McCaffrey, Dalvin Cook, Austin Ekeler, Joe Mixon, Leonard Fournette, James Conner, Aaron Jones, and even fantasy-viable role players like DOnta Foreman and Jamaal Williams get a year older with each passing season and few new backs entering the league to take their place.

This year, I wanted to talk about one of my most important beliefs in dynasty and how that belief is shaped by my knowledge of regression. The belief is expressed in some quarters as "talented players tend to shine eventually" or "good players get theirs". Personally, I like to call it the Dr. Ian Malcolm Hypothesis after Jeff Goldblum's character in Jurrasic Park. Confronted by a scientist over his concern that the dinosaurs of Jurrasic Park might begin to breed despite all the dinosaurs in question being female, Dr. Malcolm is asked how that could happen. Malcolm replies that he doesn't know but that "life finds a way".

I often feel similarly about talented young wide receivers. If there's a talented young receiver in a terrible situation, I tend to remain quite high on their prospects going forward. If confronted and asked how I expect them to become productive in such terrible circumstances, I respond that I don't know, but life finds a way.

Why do I believe this? Let's go back to one of the first lessons of Regression Alert. Some factors that contribute to production are intrinsic and remain stable between samples. Other factors are largely noise or luck and tend to fluctuate between samples. Identifying regression is about locating and anchoring to the stable elements while avoiding getting seduced by the noise.

When it comes down to intrinsic factors, there are few things as intrinsic as raw talent. Good players stay good to a greater degree than lucky players stay lucky. Situation changes; talent endures. And to illustrate the Ian Malcolm hypothesis in action, I wanted to look at a single draft class and walk through just how much situations changed in each player's first three years. So let's revisit the top 12 players from the 2020 WR class and compare where they started to where they are today.

• Ignoring for a moment the choices he made and their tragic consequences, Henry Ruggs was drafted in 2020 as a deep threat for a quarterback who wouldn't throw deep. Within his first three years, Derek Carr developed a wicked deep ball, head coach Jon Gruden (who was entering Year 3 of a 10-year fully-guaranteed contract) was fired, Carr was given a monster long-term contract, and now Carr is not only benched but apparently banished from the team as the Raiders see what they have in Jared Stidham.
• Drafted into a team with Vic Fangio at head coach, Jeudy, in three years, went from Drew Lock at quarterback, to Teddy Bridgewater, to no-doubt future Hall-of-Famer Russell Wilson, to whatever simulacrum has been trying to pass itself off as potential Hall of Famer Russell Wilson. Jeudy will open 2023 under his third head coach.
• It's hard to remember now, but there were questions about how CeeDee Lamb would be able to stand out in a receiving corps that already featured Amari Cooper and Michael Gallup, both of whom were 26 or younger and both of whom went over 1100 yards the year prior. Cooper lasted two years before getting traded to Cleveland, Gallup hasn't been healthy very often or effective when he was, and the Cowboys passing game has been the CeeDee Lamb show.
• In just three seasons, Jalen Reagor has gone from Carson Wentz to Jalen Hurts to Kirk Cousins after getting traded to the Vikings.
• Justin Jefferson's situation has actually been very stable during his short time in the NFL, though some of the concerns surrounding him look laughable in hindsight. Some (including the Eagles, who picked Reagor over him) questioned whether he'd be able to transition to outside receiver. The bigger concern was that the Vikings were a low-volume passing offense and Jefferson shared the field with Adam Thielen. Minnesota ranked 30th and 27th in pass attempts in 2019 and 2020, and Stefon Diggs had just forced his way out of town in part over frustration at his lack of involvement; Minnesota ranks 11th and 3rd in two seasons since.
• Brandon Aiyuk seemed to have a wide-open path to the top of the depth chart in San Francisco, but the emergence of Deebo Samuel in 2021 (1700 yards and a first-team All Pro award) greatly complicated that. Aiyuk went from Jimmy Garoppolo at quarterback to Trey Lance, back to Jimmy Garoppolo, back to Trey Lance, and back to Jimmy Garoppolo, with stops along the way at a rotating cast of 3rd-stringers.
• When Tee Higgins joined the Bengals, nobody knew whether rookie Joe Burrow would be any good after just one strong season in college. Burrow showed flashes early and Higgins looked set to be his top wide receiver for years to come until the Bengals took Ja'Marr Chase and relegated Higgins to a sidekick role. Then expectations were that Higgins wouldn't be able to produce behind Chase only for the two to develop into one of the Top 3 duos in the NFL.
• Michael Pittman has seen the Colts bring in three different past-their-prime quarterbacks in his three seasons, going from Philip Rivers to Carson Wentz to Matt Ryan. Next year he'll undoubtedly be working with his fourth different quarterback. Also, his current head coach was coaching high school just a handful of months ago.
• Laviska Shenault was drafted to a team with Gardner Minshew at quarterback, which didn't inspire much confidence. After the Jaguars were terrible his rookie year they were positioned to draft one of the best quarterback prospects in recent memory in Trevor Lawrence, which was viewed as a huge boost for Shenault. It might well have been, except Shenault was traded to the Carolina Panthers and he now plays with Sam Darnold or Baker Mayfield (ironically, two quarterbacks who would have been viewed as a positive back in 2020 when Shenault was drafted).
• When he was drafted by the Broncos, it was assumed that K.J. Hamler would have plenty of competition. The team drafted Noah Fant 20th and Courtland Sutton 40th in 2019, then followed by drafting Jerry Jeudy 15th and Hamler 45th in 2020. Within three years, Fant would be gone, and Sutton and Jeudy would be considered disappointments. But it wouldn't matter because Hamler wouldn't be able to stay healthy. (He also experienced the same quarterback rollercoaster as Jeudy.)
• Drafted to help fill the void left by Antonio Brown, Chase Claypool landed with a Hall of Fame quarterback in Ben Roethlisberger and a wide-open depth chart, competing with Diontae Johnson, James Washington, and JuJu Smith-Schuster. Within three years, Johnson has established himself as a target magnet, and while Smith-Schuster is gone, new rookie George Pickens has become the hot new thing. Roethlisberger fell off a cliff and is also gone, but it doesn't matter because Claypool is the fourth of the Top 12 receivers who is no longer on the team that drafted him.

There's nothing really special about the 2020 class; this is just the kind of turnover the NFL sees in three seasons. Three of the twelve receivers have already been traded, and a fourth is in jail. Five of the twelve have entered their three seasons with three different presumed starting quarterbacks, while just three of the twelve have had the same starting quarterback the entire time. Teammates who were viewed as threats have been hurt, traded, or just underperformed. Teammates who were not viewed as threats have broken out and demanded a larger role.

It's easy to forget all of this when we look back. It's easy, knowing what we know now, to underrate just how much of a threat we thought Michael Gallup posed to CeeDee Lamb's production, how worried we were about Joe Burrow (or, later, about Ja'Marr Chase), how much of a positive many considered playing with Carson Wentz instead of Kirk Cousins to be.

Valuing a dynasty receiver based on what his situation is today assumes that today's situation will be roughly similar to tomorrow's situation. But as you can see, that's just not the case. Situations change more than you'd think, so the best move is to bet heavily on underlying talent and hope that life somehow finds a way.