clock menu more-arrow no yes

Filed under:

The Trail Blazers May Be Worse Defensively Than We Thought

New, comments

The Trail Blazers have clearly struggled to defend opposing teams, ranking last or near-last in many statistical categories. Here’s a look at why.

NBA: Portland Trail Blazers at Chicago Bulls Caylor Arnold-USA TODAY Sports

The Blazers currently sit one game above .500, with fans feeling mostly disappointed at the slow start. The offense is as good as always but the defense has been a flaming dumpster fire that’s spilled over and is threatening to burn down the nearby forest full of endangered species.

Much like a forest fire, this problem proved too daunting to tackle in a single week. The goal of this check-ins is to lay out the statistical changes in the team’s profile and then explore why those statistics have changed by breaking down game film. This marriage of analytics and “eye test” is where the best insights come from.

Today, we start with the Blazers’ statistical profile. Next week, we’ll connect the statistical changes to defensive principles on the floor. Let’s get started!

Team Defense

Defensive Rating: 109.6, no. 30 (105.6, no. 21st)

*note: all stats are from stats.nba.com unless otherwise noted.

It’s important to note that the baseline from the 2015-16 season is not the ultimate goal. We’ll be comparing the statistics to last year and discussing how the Blazers can get back to where they used to be, but that would be just a small step to where they need to be. They required substantial improvement, and yet they’ve fallen off dramatically.

How dramatically you ask? Here’s one stat to knock your socks off: According to basketball-reference.com, the 2008-09 Sacramento Kings were tied for the worst Defensive Rating (DRTG) in NBA history. To keep the numbers consistent, that team’s DRTG, according to stats.nba.com, was 111.9. That’s 2.5 points better than the Blazers’ defense during the twelve-game stretch between Aminu’s injury and Portland’s off-day practices. Ouch.

Four Factors

  • Effective Field Goal Percentage Allowed: 51.4 percent, No. 22 (50.3 percent, No. 15)
  • Opp. Turnover Rate: 12.6, No. 28 (13.4, No. 25)
  • Defensive Rebounding Percentage: 75.8 percent, No. 22 (76.2 percent, No. 13th)
  • Opp. Free Throw Rate (Opp FTA/Opp FGA): 0.314, No. 27 (0.307, No. 28)

Perhaps surprisingly, the Four Factor profile looks fairly consistent. The Blazers haven’t fallen off in one area in particular, they’ve just gotten a little worse at everything. Things have gone from bad to worse in the case of free throws allowed and forced turnovers. Portland has died from the death of a thousand paper cuts.

Wait...who are we kidding? it’s been more like the death of thousand daggers to the back, but you get my point.

The worst blow has got to the be the dip in Effective Field Goal Percentage Allowed (EFG%) for two reasons. First, it’s the most important category from a statistical perspective. Dean Oliver, who invented the Four Factors when trying to model wins, gave the shooting metric a weight of 40 percent. When determining who wins, almost half the battle is who shoots the best.

Second, this is what Portland’s defense is supposed to target. Coach Terry Stotts’ conservative scheme punts on turnovers in order to stay at home. The goal is to limit the most efficient shots and force lots of contested midrange jumpers. That goal should lead to a low effective shooting percentage, and without that, the scheme has no chance of success.

If we want to understand what’s going on with the defense, we need to unpack that number.

The most striking number is that of the midrange attempts. These are the shots Portland is trying to force, but they’re down 4.6 percentage points. That might not seem like a big number until you look at the ranking. Despite an overall bad defense, Portland was elite at forcing long 2-pointers last year. Their biggest strength has become a weakness.

That 4.6 percent of shots has been redistributed to two of the worst spots: The restricted area and the 3-point line. Corner threes are thankfully down but that is a minor victory. If we assumed Portland opponents shot a league average percentage from each spot, this change in distribution would represent a 0.71 percentage point increase in Portland’s EFG% Allowed. Again, that may not sound like much but a mere 10 percentage points often separate the best and worst defenses in the league.

So the team’s EFG% Allowed has gone up 1.1 percentage points; where is the rest of the increase coming from?

Not only have opponents been getting better shots, they’re also making them at a higher rate. That’s especially true in the paint. Portland was last in that category last year but they’ve still managed to get over six percentage points worse. Part of me wants to say that number is crazy high and can’t continue. The other part of me can’t believe how much space other teams have had inside and definitely thinks that could continue.

One number that might be mercifully unsustainable is opponent’s long distance shooting. Teams are shooting 45 percent against Portland on wide-open threes, the second highest number in the league. That number should regress towards the mean, pulling down Portland’s allowed 3-point shooting percentage.

Play Type

Anyone who’s been watching the games probably isn’t surprised by this profile. The stats paint a picture of, well...the paint. Portland’s doing a much worse job defending it compared to last year, and that’s the main reason for their early season slide.

But how are teams attacking the heart of the Blazers’ defense? Are they bullying them on post-ups or attacking from the outside? Are they cutting off-ball or beating individual defenders one-on-one?

*Post-Ups and a few other categories haven’t changed much so I left them off for brevity’s sake (rolls eyes at the concept of brevity in an article too long for one post).

Compared to last year, teams are attacking Portland more frequently in isolation and out of the pick-and-roll. They’re almost dead last in both categories. Surprisingly, transition opportunities haven’t spiked despite the numerous face-palm plays running through my head.

Those changes aren’t great since Portland struggles to defend both types of plays and is allowing more points per possession (PPP) compared to last year:

But holy bramble bushes, look at that cut number -- 1.57?! That’s not just last, it’s far and away the worst. The next closest is the lowly Brooklyn Nets, at 1.38. Portland also has the ignoble honor of being dead-last against off screen actions as well. “Off screen” typically means a shooter got open after scurrying around a bevy of off-screens. Just think JJ Reddick and you’ll have the idea.

Those are bad -- like really bad -- but they only represent a small portion of the plays. A big drop on a few plays might have less of an impact than a small drop on many plays. Isolations and pick-and-rolls have both worsened while increasing their share of the pie. That’s not a good recipe and it makes me think of one thing -- drives.

Pick-and-roll and isolation plays have the same goal from the offense’s perspective. They want to get some dribbling past their man and into the heart of the defense. How well has Portland been defending these attempts? Hold onto your hats folks, cause here comes the bombshell.

Ian Levy, over at the new Step Back, made this nifty chart last year plotting each team’s defense against drives. On the y-axis is the number of drives a defense allows per game. On the x-axis is how many points that defense allows per drive.

Last year, Portland actually did pretty well defending drives. They’re in the best corner of the graph where teams not only limit the number of drives but give up relatively few points when they do happen.

Here’s that same graph, but I added Portland’s numbers from this year.

Didn’t I tell you a bombshell was coming? That upper-right corner could be called the “Danger Zone” and Portland is flying into it faster than Tom Cruise late for a beach volleyball game. Drives are shredding Portland’s game plan and Stotts’ serenity on a nightly basis.

Individual Defense

How much of this can be blamed on Portland’s lead guards? It’s still an open question if Portland can create a top-10 defense with their current backcourt. Neither one is dissuading many doubts at this point. If anything, their defensive profiles have gotten a little worse.

McCollum’s inability to defend off screen actions is particularly alarming. This was one of the tandem’s few strengths! Last year, CJ could be trusted to track shooters around screens but he’s dropped into the bottom quartile. In a show of solidarity, Lillard has joined him there. If the team is ever going to reach elite status, these numbers will have to change.

But right now the struggle is to get back to respectable and we need to cast a spotlight on some of the rest of the roster. Pretty much the whole rest of the roster, actually. The entire bench of Allen Crabbe, Evan Turner, Ed Davis, and Meyers Leonard is getting worked one-on-one. They’re all in the bottom third in defending isolation plays. To put that in perspective, Portland didn’t have a single rotation player in the bottom third last year.

Ed Davis’ fall from grace has been particularly drastic. He was up there with Al-farouq Aminu as Portland’s best defender last year, coming in as the sixth-highest rated power forward in ESPN’s Defensive Real Plus Minus. So far this season he’s dropped all the way down to No. 83. His two main jobs, to protect the rim and defend the pick-and-roll, have been disasters. He’s currently in the 2nd percentile (!) in terms of defending the roll man and is allowing opponents to shoot 59.3 percent at the rim. Aminu’s return will certainly help but Davis returning to form could be just as significant.

One of the few semi-bright spots has been Meyers Leonard, of all people. Much maligned for his defense, Leonard has made some positive strides. Stotts is matching him up almost exclusively with centers and this shift is helping Meyers stay close to the basket. He’s responded by shoring up two of his biggest weaknesses. Not only is Leonard defending the pick-and-roll better (see below), he’s also allowing a paltry 40.3 percent at the rim.

Meyers Leonard’s Key Defensive Statistics:

That improvement has helped Leonard become a net positive on the defense, as estimated by ESPN’s Real Plus-Minus. No one expects Meyers to become a defensive anchor anymore. The new hope is that he can play well enough to stay on the floor and allow his offensive gifts to shine through. It’s taken awhile, but Leonard is slowly getting there. Now if he could just hit a 3-pointer.

Moving Forward

The numbers paint a pretty gruesome picture but there are some positives to take away. Aminu is coming back. Ed Davis won’t be this ineffective all season. Pretty much the entire team has had better numbers in the past, indicating it’s reasonable to expect some improvement. And the one player who has consistently struggled seems to be getting his footing. All of the mistakes are fixable and a turnaround is certainly possible, and perhaps even likely.

Portland has shown signs of this potential their last two games. After multiple days of practice, they’ve come out with a greater sense of urgency and precision. It will be interesting to see how they fare during the upcoming road trip and how Aminu’s return affects things. If nothing else, it will give us lots to comb through for next week.


Blazer’s Edge Night 2017

Want to assist us in sending 2,000+ underprivileged Portland-area kids to a Trail Blazers game this spring? Check out Blazer’s Edge Night 2017 for information on how to get involved, and help spread the word!