Superfantasy

A read-only leaderboard and matchup analysis tool for the members of one private Yahoo Fantasy Basketball league. Running since November 2023.

What it does

Our league is 16 teams, 9-category head-to-head. Yahoo shows you your own matchup and the standings, but not how a week's performance would have fared against the rest of the league. This reads our weekly category results and builds the views we actually argue about:

Alternate Universe — for a given week, compares a team's category totals against every other team, not only its actual opponent, giving the expected win-loss-tie record it would have had against the full field.
Power Rankings — that expected record aggregated across the season, ranking teams by performance rather than by schedule luck.
Medal Board — a season-long leaderboard awarding gold, silver and bronze in each category, each week.
Box plots and season totals — the distribution of every category across the league, so you can see where a roster genuinely stands rather than guessing.

Where it's going

It gets extended whenever the league gives us a new argument to settle. Planned next: comparing two rosters to show which categories a trade would actually move, and flagging waiver-wire players who would fix a specific category weakness. Both are analysis built on the same read-only data — the app suggests, and every move is still made by hand in Yahoo.

Scope

AccessRead-only — never writes to Yahoo
UsersMembers of one private league (up to 16)
LeaguesOne private league I play in
HostingA Streamlit app; not a public service
Commercial useNone
SourceRhinoffensive/superfantasy

Data used

Only data from the single private league my own Yahoo account belongs to. Responses are cached locally to keep request volume low. Nothing is redistributed.

Endpoint	Purpose
league/scoreboard	Weekly category results — the core of every view
league/settings	Categories and roster slots, so nothing is hardcoded
league/standings	Official standings alongside the computed ones
team/roster	Rosters within the league
players/stats	Season statistics, for category context

Transactions

The app makes no roster moves. It does not add, drop, or trade players and does not set lineups. Every transaction is made by hand in the Yahoo Fantasy interface. All output is advisory.