While ESPN's new real plus-minus (RPM) is useful at both ends of the floor, it's disproportionately useful at the defensive end because so much of what makes for good defense can't be captured by the box score or even necessarily credited or blamed on an individual player on a single play. To wit, my WARP rating explains half the variation in offensive RPM, but less than 40 percent of the variation on defense.
By capturing the impact an individual player has on his team's defense when on the court, adjusted for teammates and opposition -- along with box-score stats that predict those ratings -- RPM offers a much more complete measure of defensive contributions.
For the most part, current results (which include past seasons, but are weighted more heavily to this season) conform to conventional defensive wisdom. Of the league's top seven players in defensive RPM on a per-possession basis, three have been Defensive Players of the Year, including Kevin Garnett (+5.9), reigning winner Marc Gasol (+5.0) and Dwight Howard (+4.9). Two more, Tim Duncan (+5.2) and Andre Iguodala (+4.9), have been picked for the All-Defensive Team, and Andrew Bogut (+5.0) might join them this year, leaving only league leader Larry Sanders (+6.3) -- whose impressive 2012-13 performance outweighs his disappointing 2013-14 campaign -- as an exception.
As important as RPM may be to evaluating defense, it's still just one of several measures that together can help us assess a player's defensive value. In fact, my Defensive Player of the Year and All-Defensive Team picks for this season, which are based on a combination of stats and scouting, include only two of those top seven players. Let's take a look.
Point guard
Rubio
First Team: Ricky Rubio, Minnesota Timberwolves
Second Team: Patrick Beverley, Houston Rockets
Honorable Mention: Eric Bledsoe, Phoenix Suns; Avery Bradley, Boston Celtics; Chris Paul, Los Angeles Clippers