rosterOS Best Ball Overlay

Best Ball draft overlay for Underdog and DraftKings: live player grades, roster guidance, stack analysis, and exposure tracking.

RosterOS is a free, private draft overlay built for Underdog and DraftKings best ball drafters. It sits inside your draft room and combines live board context with ADP, rankings, and tournament upside data so you can make faster, smarter picks on the clock. See value vs reach, roster fit, position scarcity, stack opportunities, draft timing, and portfolio exposure all in one place without switching tabs or doing mental math. WHAT IS IN THE OVERLAY PLAYER BOARD Live board with search, position filters, and sort by Rank, Grade, or ADP. Grade-driven layout for fast scan-and-decide workflows. Expanded rows for deeper pick context when you want it. PLAYER BADGES STK (Completes a Stack): Appears when a pick completes a same-team stack. Shows on a QB when you already have that team's skill player, or on a skill player when you already have that team's QB. LEV (Leverage): RB-only. Highlights the best handcuff behind an early-round RB drafted by another team in the room. QB (His QB Is Still Available): WR/TE/RB-only. Flags skill players whose quarterback is still on the board, keeping a stack path open if you take the pass catcher first. BYE (Bye Clash): Warns when a pick lands on the same bye week as players you already roster at that position. GRADE PILLS Value or Reach: How the pick price compares to ADP. Fits Build or Off Build: Whether the pick supports the shape your roster is taking. Won't Last or Can Wait: Whether this player will still be there at your next pick. Stack pills: Same-team correlation opportunities tied to your current roster. Anti-Stack: Flags picks that work against what you have already built. SMART PICK GUIDANCE Take Now or Can Wait: The overlay prices your future picks against live ADP, so it can tell you when a position's window is closing and when the value survives to your later turns. QB room management: It knows when it is time for your QB2, when your QB room is already set, and when a third quarterback actually adds weeks instead of just a roster spot. Target Roster: Per-position pace that adjusts to your picks and the live board. Each position reads on pace, behind, or set, with the reason in plain language. Hedge warnings: "Hedges your..." tags when a pick mostly bets against a player you already drafted. TOURNAMENT UPSIDE SIGNALS Every player carries signals from full-season simulations: spike-week rates, startable-week rates, playoff-week ceilings, late-season ramps, and weekly floor impact. Tags like "Playoff spiker," "Heats up late," "Fills your weak weeks," and "Raises your weekly floor" tell you what a pick does for the weeks that decide tournaments. STACKS TAB Your active stacks grouped by team. Available QB stack targets that pair with your roster. Back-stack candidates: take the QB now while his pass catchers are still on the board. ROSTER TAB Emerging Build: The draft pattern your roster is starting to form. Capital by Position: Where your picks are going positionally. Roster View: ADP value and rank value per pick, by position. Combo Ownership: How your player pairings compare to the field so you can spot chalk and find differentiation. DRAFT PREFERENCES Strategy Preference: Set positional tendencies by position group. Rank Trust: How much weight grades put on your rankings vs ADP. Very Low to Very High. Stack Aggressiveness: How hard the overlay pushes stack and correlation opportunities. Very Low to Very High. Playoff Stacking: Tune how heavily the overlay weights playoff-week correlation paths. Week 17 Boost: Tune how much favorable Week 17 situations factor into grades. Capital Penalty: How much roster concentration is penalized in the grading. HOW IT WORKS Opens automatically when you join an Underdog or DraftKings best ball draft. Reads live board context, including each site's own ADP, and applies your preferences in real time. Updates grades, badges, stack signals, timing calls, and roster feedback as picks happen. GETTING STARTED Install RosterOS and pin it to your Chrome toolbar. Open the popup and run through the quick onboarding. Join any Underdog or DraftKings best ball draft and the overlay appears automatically. Use the Player Board, Stacks, Roster, and Draft Preferences tabs during your pick windows. If the overlay does not show up, refresh the draft tab and confirm Overlay Enabled is on in the popup. SYNCING YOUR PORTFOLIO Underdog: Visit any Underdog page while signed in and RosterOS picks up your session automatically. No password needed. Hit Sync from Underdog to pull your full draft history in one click. DraftKings: While signed in to DraftKings, hit Sync and RosterOS pulls your best ball entries using your existing session. No password, no credentials stored. Filter by tournament type to focus on a specific part of your portfolio, and re-sync anytime after you finish new drafts. UPLOADING A CSV INSTEAD Export your draft history and upload it under Exposure CSV in the popup. Apply tournament filters to focus your exposure view. Swap or remove it anytime. CUSTOM RANKINGS Upload a rankings CSV with Name and Rank columns, for Underdog, DraftKings, or both. RosterOS reports exactly which names matched each site's board, so nothing silently misses. When your rank and the model disagree on a player, the board says so with both numbers side by side. Players not in your file keep RosterOS ranks. Replace or clear anytime. WHY BEST BALL DRAFTERS USE IT The pick clock is short. RosterOS puts everything you need in front of you so you are not guessing. Value and reach calls get easier when the context is right there on the board. Now-or-later calls are priced against the live room, so you stop paying sticker price for positions that would have waited. Stack and back-stack paths are flagged automatically so you never miss a correlation window. Your portfolio exposure is built in, so you can see when you are doubling up on pairs you already own. Playoff upside, spike weeks, and Week 17 leverage are baked into your build decisions from round one. FREE AND PRIVATE Free to use with no account required. Your session and draft data never leave your browser. Everything is processed locally on your device. Your Underdog session token lives only in session storage and is deleted automatically when you close your browser. Preferences and uploads are stored in extension storage, not on any server. IMPORTANT NOTE RosterOS is built for Underdog and DraftKings best ball drafts. It is not affiliated with, endorsed by, or sponsored by Underdog or DraftKings.