Photo: Joe Nicholson, USA Today Sports

Gambling on the NFL is big business, especially after a 2018 Supreme Court decision striking down a federal ban on sports betting. Recent estimates suggest that as many as 46.6 million people will place a bet on the NFL this year, representing nearly one out of every five Americans of legal gambling age. As a result, there's been an explosion in sports betting content, most of which promises to make you a more profitable bettor. Given that backdrop, it can be hard to know who to trust.

Fortunately, you can trust me when I promise that I'm not going to make you a more profitable sports bettor. And neither will any of those other columns. It's essentially impossible for any written column to do so, for a number of reasons I detailed here. (I'm not saying it's impossible to be profitable betting on the NFL, just that it's impossible to get there thanks to a weekly picks column.)

This column's animating philosophy is not to make betting more profitable but to make betting more entertaining. And maybe along the way, we can make it a bit less unprofitable in the process, discussing how to find bets where the house's edge is smaller, how to manage your bankroll, and how to dramatically increase your return on investment in any family or office pick pools (because Dave in HR and Sarah in accounting are much softer marks than Caesar's and MGM).

If that sounds interesting to you, feel free to join me as we discuss the weekly Odds and Ends.

Remember Those "Under" Bets?

Four weeks ago, I noted that under bets were winning at a tremendous rate and suggested that this didn't mean we should necessarily start mass-betting unders because Vegas was adjusting the under bets in response. Two weeks ago, I noted that, since my observation, unders had gone just 15-14, so if you'd noticed the trend and started mass-betting them, you would have lost about 2% of your bets over the two prior weeks. Since then, however, unders have started hitting like crazy again, going 16-11 in the last two weeks; mass-betting unders over the last two weeks would have returned a 13% profit.

(This is the kind of selective endpointism that gambling touts love; if you had mass-bet unders over the ENTIRE four-week span your profit would have been 5.7%. No reason why you should count the good weeks but not the bad ones.)

There's obviously something weird going on with NFL scores this year, and while Vegas has clearly noticed and is adapting, the weirdness continues. This is related to the "margin of victory" component I've been noting in my Regression to the Mean column; six of the ten weeks so far this season have featured final scores that were, on average, closer than ANY of the eighteen weeks last season. (Including each of the last two weeks when Under bets have been doing so well, which is not a coincidence.)

Scoring is down considerably; teams are averaging 21.9 points per game, which is down from 23.0 points per game last season, and that underrates the size of the drop because NFL scores are typically at their highest in September and October before declining slightly late in the season (due to quarterback injuries and the arrival of inclement weather). And lower-scoring games are naturally closer games. (A trivial example: you can't win by 14 if you only score 10.)

It seems everyone has their pet theories for why this trend is happening. Some blame the rise of cover-2 defenses and a commitment to taking away explosive plays. Others point to a (related) increase in relative rushing effectiveness, which shortens games and reduces scoring opportunities. I could point to the decline in kickoff returns, which are both less frequent and less effective, which (combined with a slightly lower interception rate) results in teams starting drives an average of 0.5-1 yards further back in 2022 compared to 2021.

My own pet theory is a rise in parity; this season, there's been a striking tendency for the teams with the worst offenses to also sport some of the best defenses and the teams with the worst defenses to also feature strong offenses, which has decreased the number of truly great teams but also reduced the number of truly awful teams.

Pro Football Reference tracks a stat called "SRS" (or "Simple Rating System") which measures how many points a team scores or allows relative to what an average team would based on strength of schedule (with strength of schedule again adjusted for second-order strength of schedule, and so on). Essentially it doesn't punish a team as much for failing to score on the Bills' defense (an estimated 6 points per game better than league average) as it does for failing to score on the Lions' defense (6 points worse than league average).

Per SRS, in 2021, there were five teams that were at least 3 points per game worse than league average on offense and also at least 3 points per game worse than league average on defense (the Texans, Jets, Jaguars, Lions, and Falcons). So far in 2022, there isn't a single team that hits both marks; only the Texans (-5.3 points on offense, -2.6 points on defense) and Panthers (-2.3 points on offense, -3.5 points on defense) are even 1.5 points below average on both units, and only the Rams (-5.1 on offense, -1.0 on defense) and Chargers (-1.2 on offense, -3.5 on defense) join them if you lower the threshold to 1 point per game worse than average on each unit.

Regardless of which cause (or combination of causes) is the true driver of the rash of close, low-scoring games this season, it seems clear that it is both a real and persistent phenomenon. The NFL typically doesn't like it when scoring is down, so I wouldn't be shocked if the competition committee tweaked things to give offenses a boost again, but that's a concern for 2023; I'd expect 2022 to continue as it has been.

I still believe that Vegas will eventually get a handle on what's going on and produce lines that erase any edge Under bettors might currently have. But in the meantime, I'll reiterate my advice from four weeks ago when first noting the trend:

Does that mean that we shouldn't be betting more unders? Again, no. Remember, unders have a long-term structural advantage. Not enough to win you money in expectation, but enough to help you lose less money. And "helping you lose less money" is the best this column can aim for, so yeah, smashing the unders is an official Odds-and-Ends approved betting strategy. It might not help much, but it probably won't hurt, either.

Lines I'm Seeing