Playoffs refers to the likelihood of a team making the playoffs.
Champs refers to the likelihood of a team winning the Super Bowl.
Offense refers to total points scored above expectation; the higher the better. If a team's offensive score is 100, they scored 100 points more than a league-average offense would score if put in similar situations.
Defense refers to total points prevented above expectation; the lower the better. If a team's defensive score is -100, they have prevented 100 points that a league-average defense would have allowed.
nERD is our calculation of how good a team really is, based on expected point differential against a league average team. If the team's nERD rating is 10, they would be expected to win by 10 points against a league-average opponent.