You know what credit needs to be taken away from? DRtg. Individual contributions to team defense is incredibly difficult to measure. Dean Oliver's inability to produce a personal stat for defense is no big crime. People have been trying to do it for years. If you have a good idea on how to do it, you should publish and you'll get an NBA front office job plus a speaker spot at next year's Sloan.
The core of the DRtg calculations is the measurement of the individual defensive stop. If you look at the definition as per
http://www.basketball-reference.com/about/ratings.html:
DRtg = Team_Defensive_Rating + 0.2 * (100 * D_Pts_per_ScPoss * (1 - Stop%) - Team_Defensive_Rating)
where D_Pts_per_ScPoss = Opponent_PTS / (Opponent_FGM + (1 - (1 - (Opponent_FTM / Opponent_FTA))^2) * Opponent_FTA*0.4)
and
Team_Defensive_Rating = 100 * (Opponent_PTS / Team_Possessions)
So, assuming uniform Team_Defensive_Rating, you want as high a Stop% as possible.
Stop% is defined as the following:
Stop% = (Stops * Opponent_MP) / (Team_Possessions * MP)
Stops = Stops_type1+Stops_type2
Stops_type1 = STL + BLK * FMwt * (1 - 1.07 * DOR%) + DRB * (1 - FMwt)
FMwt = (DFG% * (1 - DOR%)) / (DFG% * (1 - DOR%) + (1 - DFG%) * DOR%)
DOR% = Opponent_ORB / (Opponent_ORB + Team_DRB)
DFG% = Opponent_FGM / Opponent_FGA
Stops2 = (((Opponent_FGA - Opponent_FGM - Team_BLK) / Team_MP) * FMwt * (1 - 1.07 * DOR%) + ((Opponent_TOV - Team_STL) / Team_MP)) * MP + (PF / Team_PF) * 0.4 * Opponent_FTA * (1 - (Opponent_FTM / Opponent_FTA))^2
So right away, you see that since steals generally top out at 3 a game, blks around 2 and defensive rebounds can be as high as 10 for some big men, the Stops_type1 calculation inadvertently lends more weight to people who do defensive rebounding than those who play on the perimeter. It prefers big men. Further more, Stops_type1 is likely to be kinder to gamble heavy defenders rather than chest to chest defenders that don't gamble. The one attribution to forcing tough shots is the DFG% which FMwt plays in a little, but FMwt really isn't weighted heavily enough to affect the outcome of an overzealous rebounder unless you happen to play next to a center who also isn't a shot blocker. See Kevin Love.
Historically, Joe Dumars has a higher DRTG rating than Rod Strickland or Bonzi Wells, whom Bonzi btw, out strips both Rajon Rondo and Shawn Marion, whom are just slightly better than Vlade Divac... Somehow Luis Scola is in the top 250 of all time... Stacey Augmon is ranked lower than Amare Stoudemire. ALLEN IVERSION IS AHEAD OF GARY PAYTON.
And somehow, Shawn Bradley and Chris Webber are better defenders than Karl Malone.
Seriously, fsck this stat.
Dean Oliver devised this stat well before its publication in Basketball On Paper, which was in 2004. What he, through his definitions, implies as a platonic defensive possession is ideally a forced turnover. If the defense can't do that, then it should limit the defense to one shot. If you have good rim protectors that are good defensive rebounders, both the protectors and the guards that gamble for steals will have high defensive ratings.
The issue with this stat is that defensive players at different positions w.r.t. to the ball handler, have different goals. Your off the ball helper that cuts off the passing lines and generating steals, the guy who is longer, will help out on defensive rebounds. Your shot blocker, will be properly represented due to the additional weights given to defensive rebounds. But the guy who really gets screwed here is the on ball defender. The great on ball defender takes away offensive options and forces the offense into inefficient shots, but the mistakes that the offense makes due to the additional defensive pressure are credited to the stealer, the blocker or the rebounder, not the actual guy who is doing most of the work.
Stop using those 'advanced stats' that are half baked.
there you go...
