For each of the following metrics, click on the subhead to be taken to the source website for more details. Other stats were determined by using my trusty sidekick, MS Excel, loaded up with standard stats available on most websites. On those, there is no link available.
Opponents’ Player Efficiency Rating
OPER is the Opponents’ Player Efficiency Rating and has been tracked by 82games.com since 2008. It tracks the production of a player’s counterpart while he is on the court. The strength of this is that it shows what the other player does offensively.
The weakness is that it also includes some of what the other player does defensively, (e.g.. blocks, steals, and defensive rebounds). Other individual metrics and team metrics thin out the impact of those factors.
The average score by point guards was 16.1.
Defensive Points per Play
Synergy tracks every play of every game of the season and, when possible (as it is not always possible), they assign an initial defender on a play. They average the number of points a player gives up when he is the initial defender, and this is represented by defensive points per play.
The average score was .90.
One conundrum has always been how to account for who is guarding the best player on the other team. While no one “always” guards the best player, some players are much more likely to be guarding the other team’s elite players, which makes them appear weaker defensively. Other defenders’ deficiencies are hidden by being put on weaker offensive players.
That can create an illusion of great defense where there is none. In fact, a player may have great individual numbers precisely because he is actually detrimental to his team.
Meanwhile, another player has his numbers go up because he is capable.
In other words, giving up 15 points to Russell Westbrook is much more impressive than giving up 14 to Derek Fisher, but the raw stats don’t tell you who was guarding whom.
Since elite offensive players tend to have a higher usage rate, players that guard elite offensive players should also have more defensive plays. By taking the total number of plays and the total number of minutes (regular and postseason combined, because Synergy just throws it all together) we can determine how many times per 36 minutes a player was the initial defender on the play. The more often he is the primary defender, the more likely he is to be responsible for guarding the player who is getting the most plays offensively.
The average score was 11.7
Total Defensive Plays per 36 Minutes
Total Defensive Plays per 36 Minutes, or TDP/36 is simply the total number of defensive rebounds, steals and blocks a player accrues every 36 minutes.
While blocks and steals can be misleading when taken to exclusively represent defense, they are an aspect of it, so they shouldn’t be discounted entirely.
Defensive rebounds are generally undervalued, although it’s also true that all defensive rebounds aren’t the same.
The defensive stats aren’t a good way to determine the totality of defense, but they are a factor and shouldn’t be ignored.
These were calculated using the raw stats available on any site carrying basic stats.
The average score was 4.8
Defensive Rating (DRtg) is the average number of points per 100 possessions a player’s team surrenders while he is on the court. The advantage of defensive rating is that it accounts for the “things that don’t show up in box scores.” The disadvantage is that sometimes it’s not the player doing those things, and he’s getting credit for someone else’s great defense.
Several sites track this, each in its slightly unique way, depending on its formula to calculate possessions. For the purpose of this study, 82games was used because the net defensive rating was also easily available and it made for consistency. Both figures can be obtained by going to any player’s team page and then clicking on the appropriate name.
The average score was 106.9
Net Defensive Rating
One way of offsetting the problems of defensive rating is looking at on/off stats, meaning how many points does the defense give up while a player is on the court versus when he is off the court? If the team gives up more points while he’s on the court, that’s bad. If it gives up fewer points, that’s good. Ergo, a negative number is a positive thing, and a positive number is a negative thing.
The problem is that sometimes players are so inept, they skew the stats of other players. Take, for example, Carlos Boozer in 2012. He had the second-best defensive rating in the NBA. Sounds great, right? The only thing is that the Bulls actually gave up 8.6 more points while he was on the court. Taj Gibson, his backup, is a tremendous defensive player, which only amplified the effect of Boozer’s shortcomings.
The ripple effect of that was that every single Bull had a worse defensive rating with Boozer than when playing with Gibson. When Gibson played with the starters, the Bulls gave up 10 fewer points per 100 possessions. The effect was that the Bulls' starters all looked inferior to their backups.
Chris Paul fell into the same kind of trap last season.
Sometimes, all that the on/off stats tell you is the difference between two players that play the same position. They have value when there aren’t such extremes like the difference between Boozer and Gibson. The other metrics help alleviate the extremes because they also indicate what a player’s personal defense does.
The average score was .7.
While most of these stats are adjusted for minutes, the problem surfaces that bench players, playing fewer minutes, can appear to be better than they are. That’s because they can spend all their energy quickly, while starters have to pace themselves. For this reason, a small penalty was exacted for every minute under 30 minutes, and a small bonus was provided over 30 minutes.
The average minutes per game was 29.6.
That concludes the WAP portion of our programming schedule. See the criteria for scouting on the next slide.