Five real-world questions a day. Instead of guessing a number, you drag two brackets to trap it in a range — a narrow range that hits scores big, a miss scores zero, so honest calibration is the winning strategy. Streaks, an emoji share grid, challenge-a-friend links, and stats that show whether your confidence matches reality. Free, no accounts, no tracking, works offline as an installable app. A one-time Pro unlock ($6.99 launch price) adds unlimited practice and the full archive.

Hi Product Hunt! I built Ballpark because trivia games reward knowing facts, but nothing rewards knowing *how well* you know them — which is the more useful skill. The mechanic comes from calibration training used by professional forecasters: give an interval, get scored on narrowness vs. hits. Most players discover they're overconfident within a week, and the stats screen shows your "trap rate" against the ideal band. It's five questions a day, same for everyone, with streaks, an emoji share grid, and challenge links so a friend plays the exact same puzzle against your score. Zero-dependency vanilla JS, no backend, no accounts — the daily puzzle derives from your local date. Launch story I'm weirdly proud of: last week players found a scoring bug where the display rounded differently than the scoring engine. I fixed it same-day, made their exact screenshots into permanent regression tests, and comped them Pro. A game about being right has to hold itself to that standard. Happy to answer anything about the scoring design or the adversarial fact-checking pipeline behind the questions.

One proof point I have to share: last week The Hustle featured Ballpark in their newsletter and ~7,000 readers showed up. About 70% of people who start the five questions finish all five, and watching readers fire challenge links at their coworkers was the best day of the project.

Also, for anyone who wants the extras: 30% off Pro today with code

PRODUCTHUNT.

Also, for anyone who wants the extras: 30% off Pro today with code

PRODUCTHUNT.

Ballpark — the daily estimation game

The daily game that measures how overconfident you are

The daily game that measures how overconfident you are