4. Defensive Rating (DRtg) is essentially the answer to the question, "If Player X were on the floor for 100 possessions, engaging in his normal rate of plays, how many points would his TEAM yield? The lower a DRtg, the better. Because defense is a team concept, a player's DRtg is largely based on team performance. So, if a player's DPoss% [the portion of plays he directly engages in] is 20.0, then 20 percent of his DRtg would be based on those plays alone, and 80 percent would be based on the team's overall defensive performance.
5. In any given game, credit/blame had to be assigned for a number of misses/baskets to the "team" as a whole, such as wide-open misses, or points scored on solo-runout fastbreaks, or putback points where one player can't be blamed for a missed boxout. All of those "team" possessions needed to be factored into DRtg, as well as the team's overall performance. DRtg should be assessed only within the context of a team, not across teams, and small variations should be viewed as significant. (For example, a player whose DRtg is much better than the tam's overall rating should considered a great defender, and the few players whose DRtg is lower than their team's should be considered liabilities.
