This is via his AMA (Ask me Anything) on Reddit (which was confirmed to be him)
Morey is one of the utmost minds on basketball and the use of metrics. (IMO)
What's your opinion on this?
publicly available. if theres money theres a way
Patriots Forum HOF Class of 2011
Probably because its difficult to attribute a missed basket solely to any one individual.
The PSD's Official Steve Nash Support Crew, Members: R4L
I agree I find basketball defensive stats a joke. There is a few that you can use to make points but it's hard to use it as a sole reason of someone being good. Too many factors and schemes to judge defensive using stats.
He is completely right. Defense is so much more complicated to analyze than offense. Vantage Sports is coming out with some great defensive statistics, but they aren't all encompassing. Also, this is assuming Vantage Sports isn't dead, since they didn't meet their kickstarted goal.
Has any progress been made?
If we did have a good and reliable defensive metric then there wouldn't be any argument as to who the best big man is now and for the last 10 years. Since we don't, the PPG junkies come out with ridiculous claims like Kevin Love being the best PF.
It's just insanely hard to quantify defense for a given player (especially with all the different defensive sets that teams run, what his specific role is on their D, whether a player is being used appropriately in that set by his coach, etc), but I think DRPM has definitely been on the right track: http://espn.go.com/nba/statistics/rpm/_/sort/DRPM
@Flea, RAPM has rated Duncan as the best PF in the NBA many times in the past, and currently has him in the top 4 for PF's in similar roles (not including Frye or Collison for example) behind LMA, Love and Dirk. Dirk's role was reduced this season (which can help your RPM), but he still came out #1 offensive ahead of Love at #2.
Either way, I'm all but positive that a great defensive metric exists + can be properly implemented by Haralabos Voulgaris, but he is ahead of NBA teams and their stats programs.
I agree with him.