Methodology

Court Signal is an independent NBA analytics project. It is not an aggregator of other people's ratings — the original metrics below are our own transparent formulas, and the classic metrics are sourced reference columns with attribution.

Original metrics Court Signal

Each original is era-relative: it is a z-score of a box-score formula against that season's qualified players, scaled so 100 = league average that year (like OPS+ in baseball). A 1962 and a 2024 season are directly comparable.

• CHEF — three-point dominance: quality-weighted makes (3PM/g × 3P%). Three-point era only.
• KOBE — on-ball creation load / "engine": how much offense runs through a player (usage + playmaking). The ball-dominant creator tier.
• WEMBY — defense-first box index: rim protection + defensive activity. A box proxy today; the real version needs play-by-play.
• BUCKETS — scoring punch: volume × efficiency (PTS/g × TS%).

These are v1 formulas and will be tuned. They are honest box-score estimates — powerful, but blind to lineup context. That is what CORE is for.

Classic metrics

PER, BPM, Win Shares, VORP, TS%, and USG% are public-formula metrics sourced from Basketball-Reference season tables. We show them as familiar reference points; we do not claim them as our own.

CORE — the flagship impact metric live

Box-score metrics can't see who was on the court together. Court Signal's flagship metric, CORE, is a possession-weighted impact estimate (RAPM — regularized adjusted plus-minus) built from real play-by-play: it accounts for teammates and opponents and reads in net points per 100 possessions vs. the modeled average (positive is better). See the Impact tab.

CORE covers seven independently fit seasons, 2019-20 through 2025-26. O-CORE estimates offensive impact; D-CORE is sign-adjusted so positive means better defense; and CORE = O-CORE + D-CORE. Both components are centered to a model-possession-weighted season average of zero while preserving five-player lineup predictions.

The ridge model uses Basketball-Reference OBPM/DBPM as a transparent shrinkage prior, then resamples whole games for 90% uncertainty intervals. Reliability requires both exposure and interval precision: high means at least 2,000 possessions and width at most 5.0; medium means at least 800 possessions and width at most 9.0; all other interval rows are low. Stable Basketball-Reference IDs connect Impact rows to player career pages.

CORE WAR is provisionally calibrated, not a hard-coded conversion: ((CORE - r) × possessions / 100) / k, with r = -2.005486122 and k = 35.6671204135. Those values come from 7,059 games and 180 team-seasons across the six frozen calibration seasons. The same parameters are applied to 2025-26 without retraining them. Treat both CORE and CORE WAR as research estimates, not settled truth.

Data & honesty

Historical box data is Basketball-Reference-derived. Coverage varies by era — three-point, steals, blocks, and usage simply weren't recorded in early decades, so those cells are blank rather than guessed. Nothing here is a commercial product; it's an independent research project.