The luck has run out for the Bulls defense

This was interesting work from Brian Sampson of BBallBreakdown that was published 12/30, when the Bulls were on a 10-2 run and before their current three-game losing streak. The cracks in the facade were there:

Their defensive rating since Dec. 8 is the second-best in the NBA at 100.6, which is an astronomical turnaround. Opponents also saw a significant dip in shooting by only knocking down 45 percent (10th) of their shots from the field, including 30.8 percent from downtown (second).

I warn you not to be too quick to give Chicago all the credit for this turnaround, as Lady Luck deserves a lot of it.

And indeed since, in their now 3-game losing streak, the Bulls DRating is at 115, while giving up a still-low 46% percent from the field but now over 42% from three.

Sampson went deeper into the defensive shot charts to try and find the cause of the defensive surge in the Niko’s Back era. He found that typical indicators of a better defense (points in the paint, fast break points) were actually worse during this defensive turnaround, the bigger difference was that opponents were simply not converting ‘open’ or ‘wide open’ (as tracked by NBA.com) attempts.

And even more glaringly from 3-point land, where the results are especially variable. From 12/8 to 12/30, opponents on open (and wide-open) 3-points attempts shot a head-scratchingly-bad 31%. In the past 3 games that number is at 44.5%.

It’ll be something to watch. Obvious personnel changes in the Niko era meant, well, more Niko (who’s a good defender)...but also Bobby Portis, and more importantly both in 4/5 combinations with Lauri Markkanen. Having no traditional rim protector in favor of outside shooting has proven to be outstanding offensively but we’ll have to see how the defense can suffer. There’s also been more minutes for Kris Dunn and David Nwaba, both very good defenders, and you’d think their contributions will help. But during their 10-2 run, the defensive improvement has been perhaps not as much due to them, or Hoiberg (come on, guys), but opponents simply missing.

The Bulls are undoubtedly better since “Niko’s Back”, but perhaps not to that of a low-level Eastern Conference playoffs type team, let alone among the best in the conference.