No black box. Here's exactly where every number on Gaffer Maths comes from.
Every hour Gaffer Maths syncs the official FPL API: all 600+ players, prices, ownership, injury flags, fixtures and every player's per-gameweek stats (minutes, goals, assists, xG, xA, bonus, defensive contributions).
When a new season starts, the IDs FPL uses are reset, so Gaffer Maths detects the new season and starts fresh rather than mixing seasons.
Four machine-learning models (one per position, XGBoost, trained on four seasons of history, 2022/23 to 2025/26) predict each player's points for each fixture from 20 features: recent points and minutes, starts, goals and assists, xG, xA and xGI, ICT, clean sheets, price, home/away, and the opponent's recent xG created and conceded.
Double gameweeks add up both fixtures; blank gameweeks score zero. Each projection is multiplied by the chance the player is available, using FPL's status and the expected-return date in the injury news.
Defensive contribution points (introduced in 2025/26) aren't in the historical training data, so they're added separately from each player's rate of hitting the threshold this season.
Quantile models give a range for every projection: the 10th and 90th percentile. That's where the 'ceiling' on captain picks comes from.
Transfer plans come from a mixed-integer program solved with HiGHS. For each player and each gameweek it decides squad, starting XI, captain, buys and sells, then maximises projected points minus hits.
It enforces every FPL rule: £100m budget using your real selling prices (half the profit, rounded down), 2-5-5-3 squads, max three per club, a legal formation, free transfers that bank up to five (and are kept through Wildcard and Free Hit), −4 per extra transfer, and the chips (Wildcard, Free Hit, Bench Boost, Triple Captain).
Later gameweeks are weighted a little less (they're less certain), and banked free transfers at the end of the window have value, so it won't burn transfers for tiny gains. Every plan is replayed through an independent rule checker before you see it.
Chip advice values each chip for every gameweek in view: bench points for Bench Boost, captain points for Triple Captain, and full optimiser runs for Free Hit and Wildcard.
Price predictions use FPL's own projections, published in-game this season, refreshed every hour on Gaffer Maths.
Mini-league tools fetch each rival's picks for the live gameweek to build live tables and effective ownership.
Projections are averages. A 6-point projection still blanks often. Team news, rotation and penalties change things fast, so treat the numbers as a strong starting point and stay the manager.
Gaffer Maths is an independent fan project, not affiliated with the Premier League or Fantasy Premier League.