Web app · Social Networking
Brierboard
Season-long forecasting tournaments, scored by Brier
Set a season, put YES/NO questions on the slate, have everyone give a probability, then resolve them and watch the Brier leaderboard sort out who actually knows anything. No money, no bets — free in your browser.
Stored in your browser only. Nothing you do in the web version is sent to our servers. Clear your browser data and it's gone — so export a backup from the in-app menu if you want to keep it.
This app is a community proposal.
Try the full browser version now. We build the iPhone and Android app once 100 people upvote it.
We'll email you once, when it ships. Unsubscribe anytime.
In your browser
What you can do in Brierboard on the web
Seasons, not one-off bets
Each tournament has a start, an end, a roster of forecasters and a slate of questions everyone answers.
Real Brier scoring
(probability − outcome)² averaged over every resolved question — 0.000 perfect, 0.250 coin flip, 1.000 confidently wrong.
The forecast rail
Every question shows a 0–100% rail with each forecaster's call pinned on it, and a marker where the truth landed.
Calibration, not just wins
Buckets your forecasts by what you claimed and shows how often it actually happened — yours and the whole room's.
Season awards
Best forecaster, most overconfident (claimed confidence minus hit rate), sharpest and worst individual calls.
Nothing leaves the browser
No account, no money, no sync — export the seasons as JSON or the board as CSV whenever you want.
Screens
Every screen, rebuilt for the browser
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1
Tournaments
Your all-seasons Brier score, questions you have not called yet, and every season with its leader.
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2
Season
Standings, the full slate with each question's status, and the room's calibration.
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3
Question
The prompt, the forecast rail, everyone's probability, resolve YES/NO and the per-call Brier contribution.
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4
New tournament
Name the season, set its window, list the forecasters, and read how the scoring works.
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5
Board
One leaderboard across every season plus calibration charts and the season awards.
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6
Settings
Your name on the board, the no-money promise, JSON backup, CSV export, sample data and erase.
Try it with sample data: Loads three seasons — a Fall NFL slate, an Election Night pool and a Winter Markets & Tech season — with 15 questions, 10 of them resolved, and four forecasters with deliberately different calibration. You can start fresh at any time.
Ready? It's free.
No account, no install, no subscription. Everything you do stays in this browser.
Your say
What should Brierboard do? Tell us before we build it.
Tell us what to build next.
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Questions
Is the web version of Brierboard free?+
Yes. Every screen is free to use: no subscription, no in-app purchases, no account.
Do I need an account?+
No. Open Brierboard and start using it right away. Sign in with Google only if you want to upvote an app, save it to your list, or leave a comment.
Where is my data stored?+
Only in this browser's local storage. Nothing you enter is sent to our servers, so we can't see it, back it up, or restore it. Clearing site data, a private window, or another device starts empty. Export a backup from the in-app menu to keep it.
Is there a Brierboard app for iPhone or Android?+
Not yet. Brierboard is a community proposal: the browser version is complete, and we build the iPhone and Android app once 100 people upvote it. Upvoters get one email when it ships.