Why the margin and not the win
A pool that only counts wins flattens everything: a one-point escape and a thirty-point demolition are worth the same, and by week six half the field is tied. Scoring the margin separates them immediately, and it keeps a bad week recoverable — being down twenty is a hole, not an elimination.
It also changes what a good pick is. The safest favorite is rarely the best play, because everyone has it and it only needs to win by three. The pool rewards reading a mismatch, which is a different and more interesting question than reading a winner.
One decision, every week
There is one pick to make and no slate to fill in, which is why margin pools hold people who would never complete a full card. It is also why they are unforgiving in a quiet way: you cannot hedge, and a blown pick is on the board all season.
Nothing to tally
Scores arrive off the live feed, so nobody types a result into a spreadsheet. Picks grade themselves as games go final, standings move on their own, and the commissioner finds out who won at the same time as everyone else.