Note: This article was written on 11/2 prior to the 76ers/Trailblazers game, so many of the statistics are no longer accurate. However, since Embiid was out on Sunday, I still believe that the analysis is relevant and accurate.
The Philadelphia 76ers is the only remaining undefeated team in the league, an accomplished predicated on their defense. Many analysts saw this coming, but not to the degree to which their defense is currently dominating. Before wrapping our heads around their defensive supremacy, it’s important to briefly explain a couple of statistics. For a super deep dive into these kinds of stats, check out my 4,000 word statistics explainer.
Offensive and Defensive Rating
When comparing team offenses and defenses, analysts will look at offensive and defensive rating. Respectively, these are the points per 100 possessions that teams either score or allow. By calculating these numbers per 100 possessions, we normalize the possessions so that we don’t confuse faster-paced teams with the best offenses, or slower-paced teams with the best defenses.
Currently, Philadelphia has an offensive rating of 104.2 and a defensive rating of 93.9. This means that, per 100 possessions, they score 104.2 points and allow teams to score 93.9 points on them. Finding the difference between the offensive rating and defensive rating yields the net rating which shows how many points per 100 possessions they either outscore or are outscored by teams.
The Philadelphia 76ers’ defensive rating (otherwise written as DRtg) of 93.9 ranks as the best defense in the league with Utah’s 95.2 in second. Before calling this historically great, it’s necessary to discuss relative offensive and defensive rating (otherwise written as rORtg and rDRtg).
Relative Offensive and Defensive Rating
Comparing teams and players across years is difficult, so analysts compare how teams perform relative to their years by calculating rORtg and rDRtg. This is accomplished by subtracting a teams’ ORtg and DRtg from the league’s average ORtg and DRtg. As of 11/2, league average ORtg and DRtg are 106.2 and 105.8 respectively.
By using this method, we can calculate the 76er’s rDRtg as -11.9 which means that teams score 11.9 points per 100 possessions less against the 76ers than a league average defense.
You’re not currently reacting appropriately. No, seriously, you’re not. Since 1990, the 2004 Spurs hold the best rDRtg at a whopping… -8.8: a full 3.1 points per 100 possessions less than the current 76ers! Philadelphia is currently on track to have the best defense in 30 years by an enormous margin.
Let’s look at what Philadelphia is doing on defense.
Location of Opponents’ Shots
Writers made much ado about Milwaukee’s defensive scheme last year. Essentially, the Bucks focused all of their energy into both preventing shots at the rim and limiting free throws. Milwaukee is continuing that trend again this year, but Philadelphia is carving out a new niche: preventing corner threes.
In the endless misinterpretation of the great mid-range versus three-point debate, one thing is clear: corner three-point shots are the most efficient three-point shot. The three-point line isn’t a perfect half-circle, so the corners are closer to the rim. Shots taken from the corner are 2.7 percentage points more accurate than other threes.
After four games, Philadelphia is allowing a ridiculous 9.3% of opponent shot attempts from the corners. League average is 19.6%, and the Jazz are second allowing 13.3%. By comparison, I didn’t see a single other team in the last decade allow fewer than 15%. Through preventing teams from taking one of the most efficient shots in basketball, the 76ers are building their own defensive scheme.
What is the Philadelphia 76ers Ceiling on Defense?
Not everything is perfect for Philadelphia on the defensive end. Despite having two premier post defenders in Al Horford and Joel Embiid, the 76ers allows opponents to shoot 36% of their total shots as layups. This is 8.6 percentage points worse than league average. On all shots within 3 feet of the basket, opponents shoot 70% which is 4 percentage points worse than league average.
Honestly, I doubt that either the corner threes or the paint data hold. When NBA teams scheme to shoot corner threes, it’s so difficult to limit them drastically. Conversely, Embiid alone should be enough to anchor a top-tier paint-protecting team. With him next to Simmons and Horford, nobody should ever score in the paint.
Although I don’t think the 76ers will shatter the numbers for best defense in three decades, it wouldn’t suprise me if they end up as one of the best five defenses we’ve seen since 1990. Their starting five is the most talented defensive lineup I think we may have ever seen; let’s see if they can live up to the hype of championship contender.
All shot data from Basketball Reference. All data was collected before the Philadelphia/Portland game on 11/2.