About rosterOS
rosterOS is a free, donation-supported best ball tool with two parts. The Chrome overlay grades each available player in Underdog and DraftKings drafts using ADP, your roster build, position scarcity and simulated tournament upside. The separate Draft Visualizer reads uploaded draft exports and shows exposure, CLV, combos and ADP trends. The site says draft data is processed on your device.
Features
- Live player grades with reasons (value, fit, timing)
- 'Take now' vs 'can wait' pick timing
- Positional draft capital tracker
- Build archetype advisor
- Stack leverage and exposure tracking
- Draft Visualizer for exposure, CLV and combos
Sports and sites covered
Sports
Works with
- Underdog
- DraftKings
Pricing
Free
Donation-supported
Prices as listed on rosteros.com when we checked. Confirm current pricing on their site.
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Sources and corrections
Last checked Oct 3, 2026. We build every listing from the sources below and recheck them regularly. If something about rosterOS has changed, let us know.