Methodology

Bricks is the NBA counterpart to Whiffs, applying Tom Tango's projection-evaluation principles to basketball.

Separate playing time from rate stats

Playing time is measured in minutes (and games). Scoring, rebounding, playmaking, and other outcomes are evaluated as rates—most often per minute, with shooting percentages and 3PA/FGA kept as their own rates.

Total rebounds are scored as REB/MIN along with the offensive and defensive splits. A system that publishes REB is scored on that total. A system that publishes OREB and DREB is scored on their sum.

Adjust for league context

League scoring environments change. Bricks subtracts the minutes-weighted league average from each projected and actual rate before measuring error, then reports raw, league-adjusted, and minutes-weighted league-adjusted MAE/RMSE.

Weight by minutes

An error for a 200-minute player matters less than the same error for a 2,500-minute player. Weighted league-adjusted metrics use actual minutes as weights.

Include unprojected players at league average

If a player appears in actuals but not in a projection system, Bricks assigns 500 minutes for playing-time evaluation and league average for rate stats.

SPS

SPS is Basketball-Reference's Simple Projection System. The last three seasons are weighted 6/3/1. Each rate is regressed with 1,000 minutes of league-average production, then aged around 28. Missed shots and turnovers take the opposite age adjustment. Attempts are makes plus misses, and points are computed from the makes. The published figures are per 36 minutes. Bricks also projects minutes with a Marcel playing-time split — half of last year's minutes, a tenth of the minutes from two seasons ago, and 600 minutes of prior, aged around 27 — and sets games from minutes per game after the same 6/3/1 regression. A player is projected only if he played at least one game the previous season.

ESPN

ESPN is the full-season fantasy projection ESPN stores beside its actuals, from 2017-18 on. It includes games, minutes, shooting, total rebounds, assists, steals, blocks, and turnovers. The offensive and defensive rebound split is absent, so ESPN is scored on REB/MIN and left out of OREB/MIN and DREB/MIN. Players are joined on NBA id using the fbkb_ids crosswalk.

Fantasy pages

The fantasy pages ask a narrower question: how accurate were projections for players who actually mattered in category leagues? Bricks keeps players with at least 1,500 minutes, then scores minutes, games, minutes per game, and the usual 9-cat rates (points, rebounds, assists, steals, blocks, turnovers, threes, FG%, and FT%). Playing time stays separate from rates, and the same league-average and minutes-weighting rules apply.