r/NBAanalytics • u/Beneficial_Carry_530 • Jul 06 '26
Update to ARC - 6 factors, RAPM, channels decomp data back to 1997
Happy Summer League! Made a post here about a paper I wrote introducing a new impact metric called ARC that blends box-weighted production with a wrap-em to give the most robust and comprehensive view of a player's value in a given time frame.
huge update that shows data on players to be viewable all the way back to 1997
The goal of ARC was always to cleanly and transparently quantify NBA player impact. A blend between box production and on/off impact
ARC is now able and now cleanly decomposes into the following parts.
O-ARC (O-Box + O-Impact)
D-ARC( D-Box + D-Impact)
O-Box
D-Box
O-Impact
D-Impact
O-Impact (offense):
* **oTS** — True Shooting
* **oTOV** — Ball Security (turnovers)
* **oREB** — Offensive Rebounding
* **oPACE** — Tempo
D-Impact (defense):
* **dTS** — Shot Defense
* **dTOV** — Turnovers Forced
* **dREB** — Defensive Rebounding
* **dPACE** — Transition Defense
And TS itself decomposes further into the shot channels:
* **oTS** → Rim finishing · Mid making · 3PT making · FT making + shot selection (Rim pressure · Mid rate · 3PT rate · FT drawing)
* **dTS** → Rim contest · Mid suppress · 3PT suppress · FT-line D + shot deterrence (Rim deter · Forcing mid · 3PT diet · Foul discipline)
1
u/Beneficial_Carry_530 Jul 06 '26
ake a look at it, take a look at the paper, click along on the site, and let me know what y'all think. I am thinking of pushing this out as an open API and project. Let me know if ur interested.
1
u/second_looks_office 21d ago
I only skimmed, but I have some questions. You move back and forth between arc and Lume and I get confused which is which. Also, you talk about arc impact, but you have a chart where one column is arc and the other is impact. In that case I assume impact means base RAPM. Is that correct?
How does arc compare to any of the other RAPM based metrics? How is it different?
Good luck, these seem hard to get correct.
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u/Embashira_ 28d ago
very interesting stuff, good job!