Ball Knowledge

Privacy Policy

Last updated November 3, 2026

Ball Knowledge is built to collect as little as possible. You can use the free app without an account.

Our data promise

We never sell, rent or share your personal information with advertisers, data brokers or anyone else. Your details are used only to run your Ball Knowledge account, by the services that power it (Google Firebase for sign-in, Cloudflare for hosting, Stripe for payments), or when the law requires it. If that ever changes, we'll ask you first.

What stays on your device

The wallets you follow, your alerts, your promo progress, news filters, and settings are saved in your browser on your own device. We don't see them unless you turn on lock-screen alerts (below).

When you first open Ball Knowledge we ask for your date of birth to confirm you're 18 or older. Only the result ("18 or older") is saved on your device for that check. If you create an account, your date of birth is stored with it as described below.

What we store on our servers

• Your account (optional, required for Premium): when you create an account with your email and a password, a sign-in link sent to your email, or Google, Google Firebase handles the sign-in and gives us your email address and a user ID. Firebase stores your password securely; we never see it. We store your email, your Stripe customer ID, and the settings you choose to sync: the wallets you follow, your alert size, your starred teams, and your promo progress. Firebase processes sign-ins under Google's Firebase privacy terms.
• Lock-screen alerts (Premium): if you turn them on, we store your device's push notification address, the wallet addresses you follow, and your alert size, so we can send you alerts. Turning notifications off deletes this.
• Premium: we store a random device ID linked to your Stripe customer ID, so Premium works on your devices.
• Your details: your first and last name, email, date of birth and (if you add it) mobile phone number. We use your date of birth to confirm you are 18 or older, and your name and phone only to identify and secure your account. If you answer "How did you hear about Ball Knowledge?", or arrived from a link with a campaign tag (like an ad), we save that answer or tag with your account so we know which ads and channels work. We only look at it as totals.
• Friends: your username, the friends you add and requests you send or receive, your sharing choices, and (only if you add it) your own Polymarket wallet address. Friends you accept see your username, first name and last initial, the traders you track, and your linked wallet's activity, unless you turn those off in Friends → What friends see.
• Invites: if you sign up with someone's invite, we save who invited you, so you both get your free week. The person who invited you can see you've joined because you start out as friends.
• Ratings: if you rate Ball Knowledge, we save your stars and anything you write, with your email if you're signed in (or a random device ID if you're not), so we can read it and follow up.
• Notification settings: if you turn on lock-screen alerts, we also store your quiet hours and any break you take, so we don't send alerts then.

You can change your details anytime in Account → Edit details, and delete your account anytime in Account → Delete account, which removes all of this from our servers.

Payments

Payments are handled by Stripe. Stripe collects your email, card, and billing details under Stripe's Privacy Policy. We never see or store your full card number.

Third-party data and services

Ball Knowledge shows public data from Polymarket and sports news from Yahoo Sports, ESPN, Bing News and Google News, and runs on Cloudflare. Requests to these services go through our servers, so they don't see your IP address directly. Links to sportsbooks, prediction markets, and sponsors take you to their sites, where their own privacy policies apply.

What we don't do

We don't sell your data, use tracking cookies, or use third-party advertising trackers (no Facebook Pixel or Google ads tags).

We count visits with Cloudflare Web Analytics, which uses no cookies and doesn't track you across sites. It tells us things like how many people opened a page and which site linked them there.

Your choices

You can clear everything stored on your device by clearing this site's data in your browser. Signing out stops syncing from that device. To delete your account and everything we store about you, use Account → Delete account, or email us and we'll delete it.

Contact

Email [email protected].