How Earl rates NBA teams

Earl's NBA Power Rating is a single number in POINTS on a neutral court: a team's rating minus its opponent's rating approximates the spread. It is built from a ridge-regularised least-squares fit on game margins (an SRS/Massey-style model) with a fitted home-court term, recency weighting (recent games count more), and shrinkage toward the prior season's final ratings that fades as games accrue. Weeks are cut from the season's first played game. Updates use FINAL games only and never look ahead.

Reading the number

• Rating (points, neutral field).A team's rating minus its opponent's approximates the expected margin. A +6.0 team is about six points better than average, i.e. roughly a six-point favourite on a neutral field.
• Δ Wk. Movement versus last week — ratings are anchored, so they change only as much as results justify.
• SOS. Strength of schedule — the average rating of the opponents a team has faced, expressed in points versus the league average. A positive SOS means a team has played a harder-than-average schedule; a negative SOS means an easier one. (It is not a ranking — it's the same points scale as the rating itself, so it can be negative.)
• Injuries.Earl docks points off a team's rating for key players unavailable for that week's game. Each unavailable player is worth a position-based amount (a starting quarterback is worth far more than a rotational defender), scaled by how big a role he actually plays and by how likely he is to miss the game (Out / Doubtful / Questionable, or a practice-status fallback). The docked total is shown as Inj. The rating still starts from on-field results, so the injury dock reflects who is expected to be missing going forward.
• vs the Market. Separately, Earl solves the same rating model on theclosing point spreadsof every game to produce a market-implied rating, then places it on Earl's points scale and reports the difference as vs Mkt. A positive number means Earl is higher on the team than the betting market; a negative number means the market is higher. The market is neveran input to Earl's rating — it is a comparison only.

Principles

• Every rating is decomposed into its inputs, so any ranking can be audited.
• Ratings use FINAL games only — never future results.
• Early in the season ratings shrink toward last season's finish, then stand on their own.
• Earl's written take is commentary on the number — never an input to it.

Current snapshot: NBA 2025, Week 25.