The best advice a bettor could have received during the first three weeks of the 2022 NFL season?

"Take the under."

Only 17 of the first 48 games played this season went over the Las Vegas total, working out to just 35.4 percent of all matchups. NFL games are averaging just 42.0 points per, which is down four full points from 2021 and would mark the lowest full-season average since 2006.

But even that doesn't reveal just how much scoring is down. That's because it's actually often up when temperatures are still well above zero across the country and inclement weather often isn't an impediment to offenses.

In the first three weeks of the 2021 season, games averaged 47.1 points. Now we're talking about a year-over-year difference of nearly a touchdown.

Points per game, first three weeks of season:
2022: 42.0 (35% over total)
2021: 47.1 (42% over total)
2020: 51.0 (60% over total)
2019: 45.0 (46% over total)
2018: 46.0 (52% over total)
2017: 44.0 (49% over total)
2016: 46.0 (56% over total)
2015: 47.0 (58% over total)

Oddsmakers were also a little too ambitious with their high totals last September as well, but we're still in uncharted territory by recent standards thus far in 2022.

What's going on here? Let's look at some potential factors.

Injuries?

It's hard to peg this on injuries because they happen every week, every month, every year. But it is worth noting that the NFC's lowest-scoring team, Dallas, has been without star quarterback Dak Prescott most of the month. The conference's second-lowest-scoring team, San Francisco, has also been forced to make a change under center on the fly as a result of Trey Lance's season-ending injury in Week 2.

Justin Herbert and his Chargers offense have also been hit hard, Mac Jones is hurt in New England, and Deshaun Watson remains suspended for the Browns (not an injury but a key absence nonetheless).

There weren't as many key injuries at the sport's most critical position last September. Ditto for the ninth month of 2020.

Player movement?

Superstar Russell Wilson doesn't look totally comfortable yet for a Broncos team that ranks second-last in the league in scoring. Ditto for Matt Ryan for a Colts offense that ranks dead-last in that metric. The Steelers, Seahawks, Panthers, Commanders and Falcons are also operating with starting signal-callers who weren't on their rosters in 2021 (although Atlanta's offense has actually put up half-decent numbers thus far).

Regardless, about a quarter of the league's offenses are adjusting to new quarterbacks. Wild, right? Meh. Because recent rookie quarterback classes have been so prominent, that's about the norm. However, it should be noted that offensive supporting casts look quite different in Kansas City, Miami, Las Vegas, Green Bay, Tennessee, Baltimore and Arizona following big offseason moves involving Tyreek Hill, Davante Adams, A.J. Brown, Marquise Brown and DeAndre Hopkins (who is suspended to start the year).

This would appear to tie in appropriately to the fact that the offensive decline thus far can be attributed to a drop in passing game effectiveness, which is something the league's own operations department analyzed earlier this week.

Significant offseason shakeups aren't unusual these days, but the league was certainly shaken a little more than usual this past spring. Still, you'd think that might be offset by the fact that no rookie quarterbacks have started yet in 2022.

Coaching changes?

It's worth considering that the 2022 NFL season features a record-tying 10 new head coaches, with some wholesale changes within several staffs. That head coaching change total is up from seven in 2021 and only five in 2020, but that doesn't necessarily explain why offenses are struggling more in general thus far.

Nine of the league's 32 teams now have new coaches installed to run their offenses—either in the offensive coordinator role, the head coaching role or both.

The list: Ken Dorsey (Bills), Luke Getsy (Bears), Nathaniel Hackett (Broncos), Pep Hamilton (Texans), Doug Pederson (Jaguars), Josh McDaniels (Raiders), Mike McDaniel (Dolphins), Kevin O’Connell (Vikings), Brian Daboll (Giants).

But is that an outlier? Not really!

New offensive coaching kingpins by year:
2022: 9
2021: 11
2020: 9
2019: 13
2018: 11

Age?

Thus far we've looked at three potential factors that don't appear to come together to explain the drop-off in scoring. But what about simple declines as a result of an aging star quarterback population?

Is age simply catching up to some of the league's greatest quarterbacks?

At 45 and 38, respectively, Tom Brady and Aaron Rodgers have thrown just seven touchdown passes in a combined six games. Both Wilson and Matthew Stafford haven't been right and could be beyond their primes at 33 and 34. Ditto for 34-year-olds Kirk Cousins and Ryan Tannehill, while 37-year-old Matt Ryan is the league's third-lowest-rated qualified passer.

If that group is beginning to slide, it could result in a marked decline in scoring all the way through until January.

Defenses getting better?

This is something worth monitoring as well. There are cyclical patterns in this league and it's entirely possible we're witnessing the beginning of a defensive resurgence. That analysis from the NFL's Football Operations department did note some marked changes in defensive strategy early this season, but the sample size remains pretty small.

Rule changes?

Nope. Nothing dramatic was changed this offseason that would account for a dip in offensive production.

Of course, we might also be looking at somewhat of an aberration. The 2022 season is only 18 percent complete, and a lot can change between now and January. But shakeups, injuries and (thus far) fading quarterbacks have at least partially led to a scoring slump entering October.

Now, you'll have to decide whether that means to ride that trend with unders or try to take advantage of the law of averages with a run on overs.