The good, bad and nerdy from the Portland Trail Blazers over the last week

GOOD: A DEFENSIVE SYSTEM

Even amongst the Blazers, the notion that this team would be among the NBA's best defenses in 2017-18 seemed like a bad joke last spring.

"What's funny is," Blazers wing Pat Connaughton said on Wednesday, "if you had told us at the end of last year that defense is what (would be) helping us win games as opposed to offense, then we probably all would've laughed."

The Blazers have the third best defensive rating in the NBA, allowing 99.3 points per 100 possession. The transformation of the defense from laughing stock to legit strength has propelled the Blazers to 13-8, good enough for fourth place in the Western Conference. It has been the defense that has propped up Portland's inconsistent offense this season, a notion that made Connaughton and his teammates chuckle a few months ago.

There was a time this summer when Terry Stotts and his staff considered a complete overhaul of the defensive principles he installed five seasons ago. But those discussions fizzled and instead the Blazers decided to stick with their defensive system, believing they could improve with better focus and commitment.

Stotts' decision looks prescient as the Blazers are excelling under his scheme. Portland is holding opponents to the lowest effective field goal percentage in the league (field goal percentage that takes into account the value of three-pointers). The Blazers are chasing teams off the three-point arc, allowing the second fewest three-point attempts and fewest corner three-point attempts in the NBA, according to Ben Falk at cleaningtheglass.com.

Opponents are shooting 54.6 percent at the rim against the Blazers, per Cleaning the Glass, easily the lowest percentage in the league. Nearly 38 percent of the Blazers' opponents shots are long twos, mid-range jumpers at least 14-feet from the rim. That's the profile of a good defensive team: Limiting easy opportunities and forcing the most difficult ones.

The Blazers say it's a renewed focus and commitment to improving on defense, starting with attention to details on the practice court and during film sessions.

"We're just taking more focus on the defensive end," Blazers center Ed Davis said. "And not letting the small stuff fly because that small stuff adds up."

Any discussion of the Blazers' defense has to circle back to Damian Lillard and CJ McCollum, the small, high-scoring backcourt often associated with giving up as many buckets on one end as they score on the other. But as the Blazers have grown into a consistently effective defense, Lillard and McCollum have been noticeably improved and attentive on the defensive end.

Stotts points to deflection totals and numbers of contested shots, but warns that getting too caught up in the numbers distracts from the obvious. Watch the Blazers for five minutes and it's easy to see better communication and effort to help each other defensively.

Having the guards engaged helps, having Jusuf Nurkic and Davis healthy has been crucial, but the key is the interest. The Blazers want to be a good defensive team and their commitment to an effective system has put them in position to be one.

As Davis put it: "We knew that coming into this year if we didn't turn it up on the defensive end we'd be in the same position we were in last year."

BAD: CAVEATS

It's hard to fake being a good defensive team a quarter of the way into the season, but there is reason to believe the Blazers are just that: A good defensive team and not an elite one like their numbers suggest.

While Portland is defending well at the rim, teams are getting a ton of shots in close. The Blazers have allowed the eighth highest percentage of attempts at the rim as more than a third of opponents' shots have come right at the basket in the form of layups, dunks and put backs, per Cleaning the Glass.

Although the Blazers have stymied some talented offensive teams, they have had some schedule luck. When facing the league's top offenses, Portland has had the good fortune of playing teams missing key players. New Orleans played most of the game without Anthony Davis, Indiana's Myles Turner missed the game with a concussion and Washington was without John Wall.

Portland has played the second easiest schedule in the NBA, according to ESPN.com and the easiest schedule, according to Basketball-Reference. Things are going to get tougher in the final 60 games, and the Blazers have to hope that the defensive foundation they have built is a strong one.

NERDY: AMINU'S IMPACT

In 2016-17 the Blazers were brutal defensively when Al-Farouq Aminu wasn't on the floor. When he missed 13 games in November and early December the Blazers' defense cratered to the worst in the league.

Aminu missed another 13 November games in 2017 and instead of completely wilting without their best and most versatile defensive player on the floor, the Blazers have remained impressively consistent. Over the last 13 games without Aminu in the lineup the Blazers have a 99.4 defensive rating, allowing the second fewest points per 100 possessions in the NBA during that stretch.

Last season the Blazers went from a bad defensive team to an awful one when Aminu was out of the lineup. This season they are a very good defensive team when he sits and an excellent one when he's in the game. Maintaining their stingy defense without Aminu is perhaps the most positive sign that the Blazers can sustain their defensive success throughout the season.

"It's a testament to our guys and how committed they are to playing defense," Stotts said. "And having Chief (Aminu) back should make us even better in that area."