Different scores, different grid
Football squares are shaped by threes and sevens: a handful of digit pairs are gold and a handful are nearly worthless. Basketball spreads much more evenly. Scores climb in ones and twos and threes and reach triple figures, so the last digit turns over constantly and far more of the grid is genuinely live.
The practical effect is that an NBA board has fewer dead squares and fewer obviously great ones, which makes a blind draw feel fairer to a room that has just paid into it.
Any game, any night
Football squares are usually saved for one big Sunday because there is only one game worth gathering around. The NBA plays most nights for six months, so a squares board can be run on a rivalry game in December as easily as on a Christmas Day fixture — the commissioner picks the game when they create the pool.
Claiming is blind, the digits are drawn once the board locks, and each quarter pays out on the score at the moment it ends.