FFDraftProFantasy Football Draft Pro

Your draft, live. Your league, measured.

FFDraftPro is a free, open-source Chrome extension for ESPN fantasy football leagues. Connect your league and get pick recommendations that update the instant a pick is made, plus a pre-draft war room built from your league's own draft history.

Download for Chrome (v0.3.0) View on GitHub

Free · open source (MIT) · no account, no server — everything stays in your browser.

  • 10–30 sto run the pre-draft analysis, once per season
  • 3past drafts of your league behind every opponent profile
  • 95%confidence intervals on every measured tendency
  • 0accounts, servers or trackers
The Draft Room during a live draft: on the left, recommended next picks ranked with a score, the reason each fills a starter need and a full survival bar to my pick at number 4; in the middle, the player board with position filters, rank, ADP and projection columns and Taken and Mine buttons on every row; on the right, my roster by lineup slot and my upcoming picks in snake order.
Draft Room, pick 1.04 of a 10-team superflex draft, 16 rounds. Picks arrive from ESPN's draft room as they are made.

01 Features

What it does

Two rooms and a short setup. The Draft Room runs on draft day. The Planning Room is built beforehand, from your league's own history rather than a generic rankings sheet.

On draft day

Draft Room

Recommendations are the live model score times your roster need, re-ranked the moment a pick is made. Each one shows the odds the player survives to your next pick, and whether to take him now or wait.

  • Recommended next picks. Live model score × roster need, with the chance each player is still on the board at your next turn.
  • Take now or wait. The reach score against what you can expect at the pick after this one.
  • Player board. Every player and every model column; filter by position, search by name.
  • Your roster. Lineup slots, bench, bye weeks and roster maximums, updated as you pick.
  • Picks arrive by themselves. The extension listens to ESPN's draft room, so picks land seconds after they are made. Nothing to click.
The full Draft Room window. The top bar shows the current pick, the league format and which ADP set is in use, with Undo, Paste picks, League and Sync and Reset draft buttons. Below it: recommended next picks with scores and survival bars, the player board with rank, ADP, projection and model columns, and on the right my roster by lineup slot, my upcoming picks and the draft log.
Draft Room. The clock in the top bar turns gold when you are on the clock.

Before the draft

Planning Room

A war room built from your league's last three drafts. It measures how your opponents actually draft, prices every keeper under your league's rule, then simulates the draft thousands of times to give you a plan.

  • Keeper engine. Every keeper on every roster priced under your league's rule, with the surplus against ADP and against the model.
  • Opponent tendencies. Measured per manager from the last three drafts: reach bias with confidence intervals, when each one takes a QB, position bias.
  • League-wide calibration. Whether the room prices QBs like a 2QB market, and how honest the survival odds are in this league.
  • Simulation lab. Monte Carlo drafts of your room with opponents following their measured tendencies, producing a round-by-round plan with availability odds at each of your picks and a plain-sentence cheat sheet.
The Planning Room for a 10-team superflex keeper league: a countdown to the draft, all sixteen of my pick numbers, the keeper rule in force with the evidence the analysis found for it, and the keeper-decision table listing every player on my roster with cost round, ADP rank, model rank, model surplus and ADP surplus.
Planning Room overview and keeper decision, four days before a draft.

Once per season

Get started in four steps

The setup lives inside the extension. It takes about two minutes, plus 10–30 seconds of computing.

  1. ESPN sign-in. Uses the sign-in already in your browser. It never asks for a password.
  2. Your league. Lists your ESPN leagues for the season, or takes a league ID pasted from the league's URL.
  3. Draft Room settings. Format, every roster slot, position limits, snake order, your draft slot and the matching ADP set are applied for you.
  4. Pre-draft analysis. Pulls the league's last three drafts and builds the Planning Room in 10–30 seconds.
The League and Sync setup dialog with its four steps marked done: ESPN sign-in detected in this browser, the league found and loaded with its team, draft date and league ID, the Draft Room settings applied from the league's format, and the pre-draft analysis finished, reporting 360 past picks analysed and 9 opponent profiles.
League & Sync setup, all four steps done for a 10-team keeper league.

02 Setup

Install in Chrome

There is no Web Store listing yet, so the extension loads from a folder. It takes about two minutes.

  1. Download and unzipDownload the zip (v0.3.0, about 240 KB) and unzip it somewhere permanent, for example Documents/ffdraftpro.
  2. Turn on Developer modeOpen chrome://extensions and switch on Developer mode, top right.
  3. Load unpackedClick Load unpacked and choose the unzipped folder.
  4. Pin the iconPin the green football icon. Click it to open FFDraftPro in its own window; it is also available in Chrome's side panel.

Then, inside the app

Open League & Sync → Get started and follow the four steps, once per season.

  1. Check ESPN sign-in
  2. Find my leagues
  3. Load league
  4. Run the pre-draft analysis

Updating

Unzip the new version over the same folder and press Reload on chrome://extensions. Settings, picks and the analysis are kept.

Draft day

Open the ESPN draft room in a tab and FFDraftPro next to it. Try an ESPN mock draft first: mock rooms stream picks too, so you can watch them land before it counts.

03 Under the hood

How the model works

Every number on the board comes from a stated formula, and every estimate carries its uncertainty.

Valuation

VORP + game environment + ADP + positional scarcity

Each player's score starts from value over the positional replacement level, then adds game environment, ADP and positional scarcity. It is recalculated on every pick, so the board reflects what is actually left. The recommendation multiplies it by your roster need.

Survival odds

The chance a player lasts to your next pick comes from the spread of picks around his ADP, conditional on his still being available now. The league-wide calibration card shows how well that assumption holds in your room.

League analysis

Opponent tendencies are estimated with ordinary least squares and heteroskedasticity-robust 95% confidence intervals, then used in Monte Carlo drafts where each opponent follows his measured habits. Two or three drafts is a small sample: the intervals are wide where the evidence is thin, and the analysis says so instead of hiding it.

04 Your data

Privacy

Nothing leaves your browser except read-only requests to three public services. No accounts, no analytics, no server of ours.

What is fetched

ESPN's fantasy API
Your leagues, rosters, draft history and live picks, read-only, using the ESPN session already in your browser.
FantasyFootballCalculator
Public ADP tables for the current season and for the seasons of your league's past drafts.
Sleeper's public API
Live picks, only if you use Sleeper sync.

What stays in the browser

Everything else. Settings, picks, the analysis and ADP caches are saved per league in your browser's extension storage, and nowhere else. A button in the setup dialog forgets a league's analysis whenever you like.

The source is public, so you can check all of this yourself.

05 FAQ

Common questions

Does it work with Sleeper or Yahoo?

Sleeper: live pick sync only. League connection and the analysis are ESPN-only today. Yahoo is not supported.

Is it on the Chrome Web Store?

Not yet. Install it unpacked from the zip, as described above. The source is on GitHub, so you can read exactly what it does before you load it.

Does it need my ESPN password?

No, and it never asks for one. It uses the ESPN sign-in that already exists in your Chrome profile; requests carry your own session and nothing else.

Does it handle auction drafts?

No. Snake drafts only.

Is it free?

Yes. It is open source under the MIT license, with no paid tier and no account.

What if picks don't show up?

Reload the ESPN draft-room tab and keep board scanning on. Marking picks by hand always works: search for the player and press Enter for taken or Shift+Enter for mine, or use Paste picks.