I had no idea either so I looked it up:
Net success rate in college football is an advanced analytics metric that measures a team's offensive success rate minus its defensive success rate, showing which team performed more efficiently on a play-by-down basis.
What is "Success Rate"?
Before calculating the net version, college football analysts define whether an individual play "succeeds" based on down and distance to keep the chains moving:
1st Down: Gains at least 50% (or 40% in some models) of the yards needed.
2nd Down: Gains at least 70% (or 60%) of the yards needed.
3rd & 4th Down: Gains 100% of the yards needed to get a first down or score a touchdown.
How Net Success Rate Works
Formula: Offensive Success Rate % – Defensive Success Rate %
Meaning: A positive net success rate means your offense gained "success" on a higher percentage of plays than your defense allowed to the opponent.
Value: It strips out the "noise" of rare, high-variance plays (like a lucky 80-yard broken tackle touchdown or a freak turnover) to reveal which team actually won the fundamental battle of consistent down-to-down execution.
Now I still have no idea. 😂