It would nice if ESPN and / or basketballreference finally got around to modify per or def. ratings to take advantage of the play by play data and make estimates or better estimates of individual shot defense. The original authors were never inclined to update their metrics but maybe these host organizations could or an enterprising analyst here might.
It is an open question about best way to do this but here is a suggestion:
Find the average % of total box score value represented by shot defense.
Look at players thusly:
((.65 * counterpart off. Rtg * usage) divided by lg avg off. Rtg * LG avg usage) plus .35 weighted team opponent - counterpart off. Rtg * (team - counterpart usage)
Put the parts together appropriately in the old, flawed metrics. It would be entirely new element of per. In defensive rtg it would replace the awful avg shot defense of team even when player is not on court.
I haven't thought thru the specifics of how to add to various spm's but hope one or more of those authors will try.
I know some disagree with me on this but I think some sort of inclusion or better estimate is preferable to maintaining the less accurate and complete status quo.
I don't have a personal play by play data at this point or the chops to set it up quickly and smoothly. I assume there are some at these host organizations or here who have both. Is this something Ben Alimar and his staff would be willing to take on? It would help the discussion if box score metrics and rpm were finally equally complete estimates.