If you’re betting on the NBA, you never want to blindly follow trends.

However, every so often we stumble on numbers that stand out so much that they force us to consider the underlying factors driving them.   

Sharp sports bettors will tell you that when you’ve identified a unique angle that’s not being properly factored into a line, that’s your edge.

Three years ago, the shot clock was changed to 14 seconds for offensive rebounding situations, which sped up the game and resulted in higher totals.

During the bubble season, home-court advantage became a non-factor.

Now take what we’ve seen this season.

At the start of the year, total scoring was down league wide.

The NBA made it a point of emphasis to eliminate abnormal non-basketball moves by offensive players.

Superstars like James Harden and Trae Young, who traditionally were great at drawing these shooting fouls, saw their free-throw volume take a significant drop.

This led to a drop in scoring production and a trend towards the under when it came to their player point props.

Some advantages are systematic, some are just coincidences that keep paying off. And eventually, the market adjusts for these observed changes.

As of this moment, here are three trends towards the under that have delivered an impressive enough win percentage over a large enough sample size to warrant further consideration.

Bet the under in Mavericks home games
Season win percentage: 82.6 per cent in 24 games played

For starters, Dallas has the No. 1 under percentage in the entire league for all games played (68.1 per cent). The next closest team on that list is the Warriors at 63 per cent, followed by the Cavs at 62.5 per cent.

As a base line, 68.1 per cent is already an excellent win rate, but taking that trend one degree further, the Mavs hit the under four out of every five home games.

So, what’s the correlation?

Two indicative stats are defensive rating (how many points allowed per 100 possessions) and pace (the number of possessions a team uses per game).

While it’s not significantly night and day, here are the home and away splits for Dallas:

Home Defensive Rating: 105.8
Home Pace: 95.54
Away Defensive Rating: 107.9
Away Pace: 96.78

For reference, league comparisons below:

League Average Defensive Rating: 110.1
League Average Pace: 98.1
League Worst Defensive Rating: 114.8
League Fastest Pace: 101.34

This season, Dallas has the fifth best defensive rating and second slowest pace overall. Benchmarking against the league average, games in American Airlines Center are resulting in five fewer possessions per game, which adds up over time. The data suggests the Mavs are more effective defensively and play at a slower speed at home.

The other key observation for this bet: the Mavs don’t gain an offensive scoring bump in Dallas like the majority of the league with home-court advantage. There are only five teams that have a better offensive rating on the road versus at home (Brooklyn, Minnesota, Orlando, Milwaukee and Charlotte).

We can spend hours dissecting whether Mavs fans don’t cheer loud enough, or the climate is too hot etc., but after 49 games this season, we can say with confidence that the trend towards the under in Mavericks’ home games is legitimate

Bet the under after the Suns have two or more days off
Season win percentage: 91.7 per cent in 12 games played

This trend operates on a smaller sample size of 12 games but has a whopping win percentage. If you bet $10 on the under for each game, you’d net a profit of $90.

Unlike the Mavs, who have a statistically significant season-long track record going under game totals, the Suns only do it 55 per cent of the time (21-26-0). The fact there is such a drastic difference when they have multiple days of rest should catch your attention.

Of the 12 opponents faced over this trend, six of them hit the under more than 55 per cent but the rest are neutral or on the over side, so we can rule out opponent luck.

Looking at the actual game totals, there’s a mix of lines that were on the high side around 225 and the low side with their contest against the Clippers set at 212 (fifth lowest Suns total on the season).

The data shows that when the Suns are rested, they really crank things up defensively. In these 12 games, they have a 101.35 defensive rating versus 105.4 for all other games. One can hypothesize that more practice time leads to better preparation.

What’s harder to dissect is how Phoenix’s offence also tapers off with the extra rest. Their offensive rating drops from 113.7 to 108.1. Benchmarking against other top teams, Phoenix is the only one to experience a drop off. Utah and Memphis score significantly more with the extra rest, while Golden State is offensively the same with or without rest.

If I had to pinpoint a theory, perhaps it’s game rhythm. Devin Booker’s shooting splits are the only thing that stands out. When he’s playing in back-to-backs or games with one day of rest, he shoots 45.5 per cent. In the nine games he played with more than two days off, he drops off to 38.8 per cent.

Bet the under when the Warriors are the favourite
Season win percentage: 69.4 per cent in 38 games played

As mentioned above, the Warriors are second only to the Mavericks at hitting the under on game totals. They do it at a 63 per cent rate, which is primarily influenced by their league-best defence.

What’s unique about this trend amongst the three, this one stretches over a 38-game sample size. That’s a lot of data to work with. The Warriors have been underdogs only 10 times this season.

The over hit in six of those 10 games in which they were an underdog.

Once again, as a baseline, betting the under in Golden State’s games is a good play. But getting an additional six per cent bump when they’re favourites is a useful edge.

In half of those games in which they were underdogs, Draymond Green was sidelined. His influence on Golden State’s success sometimes gets overshadowed by the show-stopping shooting of Stephen Curry.

Green was in the lineup for 31-of-38 games in which the Warriors were favoured, and there’s a reason he’s the frontrunner for Defensive Player of the Year. Their under percentage improves to 75.8 per cent during those 31 games.

Betting the under when Green is in the lineup and the Warriors are the favourite is something to consider going forward.