The Portland Trail Blazers have struggled to score this season, currently holding the No. 21 offensive rating in the league. The team’s ineffectiveness has been a surprise — the Blazers haven’t had an offense this weak since 2007, and Head Coach Terry Stotts has been applauded for his offensive acumen in previous seasons.
So, what’s gone wrong?
Last week I analyzed which opposing offensive styles have given the Blazers’ defense the most trouble. This week, I’m going to use the same methodology to try to find some patterns that help explain the team’s inability to score.
Assessing the Blazers’ Offense, Relative to the Rest of the League
Rather than looking at straight offensive rankings, I propose that we consider how the Blazers have done relative to the rest of the league. For example, everyone knows teams struggle to score against the Celtics. If the Blazers only score 95 points when they play it won’t tell us much because the entire league struggles to score against Boston.
But are there specific teams that the Blazers scored far more against than average? And, vice versa, are there specific teams the Blazers struggled against that most opponents score easily against?
Here’s a table breaking down that question:
To construct the table I took the opponents’ overall defensive rating, removed games played against the Blazers to get their rating against the rest of the league, and then compared that to how they did against Portland. The key column is on the far right (“Difference”). A positive number indicates that the Blazers scored more against that team than the rest of the league on average.
For example, the Heat have a score of 11.0. That means the Blazers scored 11 more points over 100 possessions against Miami than the rest of the league has averaged. Conversely, with a difference of -14.5, we can determine that the Blazers managed fewer points against the Raptors than the rest of the league, on average.
No Clear Pattern for Which Defenses Confound the Blazers
Last week, I was able to identify a couple strengths and weaknesses of the Blazers’ defense without too much difficulty. This week, however, the stats don’t paint a clear picture on first glance. For example, the average defensive rank of the eight teams (roughly one-third of Portland’s opponents) the Blazers have done well against is 12, and the average rank of the eight teams they’ve done the worst against is 15.
Similarly, last week I was able to use NBA.com’s four factors to draw some conclusions. This week, the results are less clear — here’s a table summarizing the average rank of the five teams the Blazers have done the best against, and the five teams they’ve done the worst against:
Note that there’s very little difference in the mean rank for the teams they’ve done well against and the teams they’ve done poorly against.
Here’s another table showing the mean rank for the same teams in a wider range of defensive categories:
If we squint a little bit, the rebounding and 3-point percentage columns might be meaningful. Specifically, the Blazers the Blazers have played well against teams that usually defend the three well and struggled against teams that defend it poorly. Similarly, they’ve rebounded well against teams that usually prevent opponent rebounds, but the opposite is true for opponents that struggle to stop rebounding.
In other words, there is a slight suggestion that the Blazers do a good job of limiting the advantage of teams that rebound well and defend the 3-pointers well, but struggle against teams that don’t usually leverage those categories.
Blazers Struggle Against Bad Teams
With that said, if we look closely at the above tables a simpler, and arguably more meaningful pattern emerges. The five teams the Blazers have scored the most against, relative to the rest of the league (Heat, Pacers, Thunder, Rockets, Clippers) have a combined winning percentage of 58 percent. The teams the Blazers have struggled to score against (Raptors, Hornets, Jazz, Kings, Magic) have a combined winning percentage of only 41 percent. In other words, the Blazers have done the best against teams averaging the equivalent of a 48 win season and the worst against teams averaging the equivalent of a 34 win season.
This pattern extends even further. The Blazers have played 26 teams this season and have a positive offensive difference against 12 teams. Nine of those 12 teams have winning records, and have a cumulative winning percentage of 56 percent. Conversely, the 14 teams the Blazers have struggled against have a winning percentage of 44 percent.
This pattern of struggling against poor teams holds up even when considering unaltered offensive rating:
This table shows that the Blazers have an offensive rating of 105.2 against teams over that are .500 or above, but have a rating of only 101.8 against teams below .500. In other words, the Blazers have the equivalent of the No. 12 offense in the NBA when they play a winning opponent, but they have the equivalent of the No. 28 offense when they play a team with a losing record.
The Blazers’ offensive struggles can’t easily be attributed to a specific type of defense. Instead, they’ve played poorly against bad teams and played well against good teams, regardless of defensive style. This could be an indication of internal rather than external problems for the Blazers; their gameplan and personnel appear to be capable of beating good teams, but they fail to execute it on a consistent basis and only “get up” for big games.
It follows that the season can go one of three ways: They can 1) continue on the current path and play roughly .500 ball from here out, 2) begin to play well against poor teams and fight for the No. 6 playoff seed, or 3) begin to struggle against all teams and fall out of playoff contention entirely. The Blazers are currently tied with the Clippers and Pelicans for the No. 7 seed in the Western Conference, so the fate of their season will likely be determined by which of those three paths they choose.