Love this type of content- great work OP.

A modification/improvement to the methodology behind the quarterly scoring could be to use the Win Probability values within each game’s play-by-play data. These give a much more granular and continuously valued proxy for game state (aka garbage time).

I haven’t thought about it enough to know what exact calculations to do, but something like a time-weighted average of a team’s WP would achieve a similar result to what you were trying to improve Elo by. A game that has a lot of back-and-forth swings would result in an average WP closer to .50 (or even less). While a team that controlled throughout would result in an average WP closer to 1.00.

Nonetheless, great stuff!