The Power Hour

Power rankings, a live waiver-wire feed and data-nerd stats for the NFL Fantasy Championship Sleeper league.

• Rankings: a 0–100 power score per team, half rest-of-season roster strength and half results. Tap a team for the reasons behind its rank, a position-group radar, its best ROS lineup, weekly scoring and simulated playoff seeds.
• Wire: every add, drop and trade, newest first. Each move is graded by the consensus ROS value gained or lost. Also shows the best available free agents and a trade ledger.
• Games: projected scores and win odds for every matchup.
• Lab: one tab, three sections. Your team (#lab/team) puts one team's season on eight animated paper widgets: playoff odds, key players, lineup efficiency, weekly scores, position groups, the schedule left, an all-play luck switch and a face off against any rival. Trades (#lab/trades) finds every 1-for-1, 2-for-1 and 1-for-2 swap that improves both starting lineups at a fair consensus value. League (#lab/league): rank flow, luck index, points for vs against, weekly finishes heatmap, position-group ranks, playoff odds, lineup efficiency, biggest games, players the experts disagree on, and waiver/trade ROI.

How it stays up to date

Data	Where it comes from	How fresh
Rosters, scores, matchups, transactions	Sleeper API, via /api/league	Once each morning (6am Central), cached on the CDN for everyone
ROS rankings (FantasyPros, DraftSharks, LeagueLogs)	api/ros.js, a Vercel serverless function	Pulled once per day (first visitor each day, Central time), then cached at Vercel's edge
This week's player projections (FantasyPros API and Sleeper, averaged)	api/ros.js, alongside the rankings	Once per day, with the rankings; they drive the Games tab

No cron job: the page requests /api/ros?d=YYYY-MM-DD, so each new day is a new cache key. If one ranking source fails, the others are still used and that response is only cached for an hour so it retries soon.

Deploy to Vercel

1. Create a new GitHub repo and push this folder to it.
2. In Vercel, choose Add New → Project and import the repo. vercel.json sets the build (npm ci, npm run build, output dist), so the other settings can stay at their defaults. The build needs Node 20.19+ or 22.12+ (Project Settings → Build and Deployment → Node.js Version).
3. Deploy. The site is at https://<project>.vercel.app; share that link with the league.

The site is built with Vite and is moving to React a page at a time (the Team dashboard is the first). To work on it locally: npm install once, then npx vercel dev and open http://localhost:3000 (or npm run dev for the page alone, without the API). Add ?demo=1 to the URL to see the saved Week 7 snapshot without calling any APIs.

Turn on FantasyPros weekly projections (one-time)

The Games tab projects each matchup from this week's player projections: FantasyPros' and Sleeper's, averaged. Sleeper needs no setup. For FantasyPros, add an environment variable FANTASYPROS_API_KEY (your key from https://secure.fantasypros.com/api-keys/request/) in the Vercel project's Settings → Environment Variables, then redeploy. Without it the Games tab runs on Sleeper's projections alone.

Turn on the league desk (one-time)

The league desk is the discussion panel beside the headlines. Anyone can read it; only managers who have opened their personal link can post, and only Dan can delete. It uses the same Upstash store as fan picks, so set that up first.

1. In Vercel, add an environment variable TALK_ADMIN_KEY: any random string of 16 or more letters, numbers, - or _ that only you know. Redeploy.
2. Open https://<your site>/#join=<that key> once on each of your devices. That signs you in as Dan.
3. In the panel, press Invite links, then New link for each manager, and DM each one their link. Opening it once signs that device in as them, and their comments show their first name and current team name.

A new link for someone replaces their old one and signs out every device that used it, so a leaked link is one click to fix. Authors can edit a comment for a minute after posting.

Turn on fan picks (one-time)

Fan votes on the Games page need somewhere shared to live. Everything else works without it; until it's connected the voting box just doesn't appear.

1. In the Vercel dashboard, open the project and go to Storage.
2. Choose Create Database, pick Upstash for Redis (the free plan is plenty), and connect it to this project for all environments.
3. Redeploy (Deployments, then the three dots on the latest one, then Redeploy) so the function picks up the new KV_REST_API_URL and KV_REST_API_TOKEN variables.

Optional: add an environment variable VOTE_SALT with any random string; it's mixed into the hashed IP addresses used for the per-network vote cap.

How it works: each phone keeps a random voter id, so voting again from the same phone switches the pick instead of adding one. One network can cast at most 3 votes per matchup (so a few friends on the same Wi-Fi still can), voting closes as soon as the week's first points are scored, and tallies stay visible to everyone. It's built for fun among friends, not to stop a determined cheater.

Tuning

What	Where
League ID, time zone	top of app.js (LEAGUE_ID, TZ)
Power-score weights	WEIGHTS in lib/engine.js
Source weights (LeagueLogs counts half by default)	SOURCE_WEIGHTS in lib/consensus.js
Rank-to-value curve	VALUE_DECAY in lib/consensus.js
Tier labels and explanation wording	tierFor and explain in lib/engine.js
Name mismatches between sites and Sleeper	NICKNAMES in lib/consensus.js

Check /api/ros in the browser to see how many players each source matched (sources.*.matched).

Files

index.html, styles.css, app.js   the site: the frame, the data and the headlines
src/                             the pages, in React (one folder each), the charts and the shared bits
lib/engine.js                    power score, explanations, playoff simulation, transaction grading
lib/consensus.js                 matches ranking rows to Sleeper IDs and blends the three sources
lib/sources.js                   parsers for each ranking site
lib/weekly.js                    this week's projections: FantasyPros + Sleeper, averaged
api/talk.js                      the league desk: one discussion thread a week, personal sign-in links
api/ros.js                       daily rankings endpoint (Vercel function)
demo/demo.json                   saved Week 7 snapshot for ?demo=1
fixtures/, scripts/              saved source data and tests (node scripts/test-engine.mjs)

If a ranking site changes its page

The parsers read specific page structures: FantasyPros' embedded ecrData, DraftSharks' /ros-rankings/load-rows table rows, and LeagueLogs' rankings table. If a site redesigns, that source shows as offline on the Rankings page and the other two carry the score until the parser in lib/sources.js is updated.

Rankings data belongs to FantasyPros, DraftSharks and LeagueLogs; league data comes from the Sleeper API. This is a personal, non-commercial league site.