What's Behind the NBA's Early Unders Rage?

The NBA season is off to a fascinating start, with superpowers struggling, upstart teams thriving, but more than anything, defenses rule the day.

Everyone’s got their theory on the offensive slump teams are experiencing. Let’s try and separate fact from speculative fiction and see how bettors can take advantage of this.

Yes, Offenses Are Down

If you’re new to the party, let me catch you up.

Offensive rating is the lowest since 2006. Effective field goal percentage is the lowest since 2016. 3-point percentage is the lowest since 1999. And free-throw rate is the lowest since ’99 as well.

So no, things aren’t going great for the offenses, and under bettors are making a killing. Unders are 59-34 (63%) on the season.

Everyone’s got a theory on why. It’s likely a combination of the different things suggested.

THE BALL

This is the first year for Wilson as the new designer of the league’s ball. After Spalding was the provider for over 30 years, the league struck a new deal with Wilson and had player input on designing the new ball. Given that there’s a change, the idea goes that this has something to do with it.

Talked to several players and all of them say the ball doesn't feel any different, for what it's worth.

— Justin Russo (@FlyByKnite) November 1, 2021

Still, it’s a discrete variable change, so something to consider.

THE CROWDS

Players in the bubble shot an absolutely incredible percentage. After, several players said that their depth perception in the studio atmosphere without the arena and all the fans made seeing the basket easier.

Last season, most arenas were empty, and most arenas are full now (or at least open to capacity seating). So between the depth perception question and the distraction of loud fans, maybe that’s the issue. Teams at home this year are shooting worse from three (34%) than teams on the road last season (36%). Maybe it’s not opposing fans and just the environment, however.

THE OFFICIATING

This is the loudest talking point, by far. The NBA not only implemented new rules to curtail offensive player “grifting” on pump-fake lean-ins and trapping arms on drives, but as a whole, the officiating has given defenders a lot more leeway.

As a comparison point, on shots around the basket that aren’t post-ups, teams are drawing fouls 4.29% of the time compared to 5.08% last season.

One analytics expert in the league told me that the foul rate differential is worth more than a point to the offensive rating dip so far this season.

Transition foul rate is down about 1% which is pretty substantial across all possessions.

Star players in particular have been upset about the physicality. Trae Young in particular has been vocal in his criticism. Eventually those criticisms will likely lead to slight or moderate shifts back in how fouls are called. 

But a stronger argument can be made that the offensive downshift we’re seeing might not be all that uncommon after all?

A NORMAL OCTOBER?

Here’s a look at how overall shooting numbers (eFG%) by area on the floor over the past five full seasons, then by the last five Octobers, then by this October.

So above the break shots are down, but corner 3 percentage is actually up, along with restricted area shooting. Mid-range shooting is the lowest it’s been, while attempts are slightly up this season.

However, compared to previous Octobers, the gap is considerably less. We see lower October figures than season averages across the board. So we can expect to see these figures regress towards the mean as the season continues. Even if the figures are lower than in previous seasons for the reasons above, they still should stabilize.

HOW TO BET THIS TREND

So the key here is not to hammer under without context non-stop, nor to try and get ahead of the inevitable turn towards the over/unders evening out.

Bookmakers told Boardroom that they don’t intend to alter course too much, yet we’re already seeing totals consistently dipping into the 210’s from a standard near 225. So as the lines move down and offensive performance improves, they’ll meet in the middle.

The key will be to watch for situations in which the offenses have started to regress and the totals still reflect the early season trend. Having a baseline to compare the numbers to is helpful, which is why you should use our award-winning app to get projections on totals.

Right now, Bradley Beal and Damian Lillard have a worse effective field goal percentage than Russell Westbrook. That’s not going to hold. Unders have been and continue to be profitable, but bettors should keep an eye for the market to overreact in the other direction.