1 · Site & player pool

Contest site

Salaries CSV (required) — the export from the site

📥 Drop the player list CSV here, or browse

DK: the player pool export · FD: the players-list CSV

Your projections CSV (optional) — overrides the site's numbers

📈 Drop projections here, or browse

Columns: an id column + a projection column. Matched by player ID.

2 · Trim the pool

Toggle off injured or players you don't want. A shorter list makes cleaner lineups and solves much faster. Players marked OUT are off by default.

Optional. Unchecks players ESPN lists as Out, on IR or suspended (tick them back if you disagree); Questionable and Doubtful just get a badge. Source: ESPN injury report.

Lock (right column) forces a player into every lineup. A locked player is in 100% of lineups, so a lock overrides any exposure cap you set for him — the lock wins. Lock sparingly; each one cuts diversity.

Optional. Adds each team's implied points (from the game total and spread) and enables the Vegas stack rules in step 3 (Tier 2). Source: ESPN, odds by DraftKings.

Filter

0 active

Turn off players below salary $

…and / or below projection

Team:

	Pos	Player	Team	Salary	Proj	Value	Impl	Lock

3 · Rules

Preset:

Loads sensible defaults for the contest type. Tweak anything afterward — nothing is locked.

Tier 1 · Site rules

# of lineups (max 150) Solve time budget (seconds)

The batch stops here whether or not it reached your lineup count. This build allows up to 240s.

Min salary used (0 = off)

Tier 2 · Within lineup

Stack the quarterback

Pass-catchers / backs with the QB

Any mix of WR, TE or RB from the QB's own team. This is the classic NFL stack — the QB's points and his receivers' points are the same throws counted twice.

…of which, specifically

WR TE RB

Leave at 0 to let the solver pick whichever teammates it likes. Set one to force the shape — e.g. WR 2 for a double-WR stack.

Bring-back from the other side

Players from the team your QB is playing against. A shootout lifts both offenses, so a bring-back turns one good game into a bigger ceiling. 0 = off (default — it's a per-QB conditional constraint like the stack requirement, and turning it on noticeably slows batch generation).

Vegas stack rules (optional)

Press Load Vegas lines in step 2 first — these stay off until lines are loaded.

Only stack teams implied ≥ (points, blank = off) Only stack QBs whose game total ≥ (blank = off)

Applied when lineups are built: no QB — and so no stack — from a team or game below the number. The blue checkboxes in step 2 don't change. Teams with no line are never filtered. Pair the game-total rule with a bring-back for shootout stacks.

No defense against my QB

No defense against any of my players

Your defense scores by stopping the offense it faces. Rostering both puts two halves of your own lineup in a zero-sum fight.

Max players from one team Max WR from one team (blank = off) Max RB from one team (blank = off)

Two backs from the same team are competing for the same carries, so one's big game usually comes out of the other's. Set this to 1 unless you are deliberately pairing a runner with a pass-catching back.

Min teams in lineup

Tier 3 · Across lineups

Max player exposure %

Cap on how many of your lineups any one player can be in. Locked players ignore this — always 100%.

Player cooldown (last K)

A player used in the last K lineups sits out the next one — forces turnover across all nine spots, defense included. 0 = off.

Max stack-team exposure %

Same cap, for the team your stack is built around — in NFL that is always your quarterback's team. On a small slate the GPP preset raises it so every lineup can still find its stack teams; type your own number and it stays.

Stack-team cooldown (last K)

A team that anchored the stack in the last K lineups can't anchor again yet.

QB rotation window

A quarterback used in the last K lineups can't start again yet. There is only one QB per lineup, so this is the single strongest diversity lever in NFL. 0 = off.

Max shared passing core (QB/WR/TE)

Cap on how many quarterback-plus-pass-catcher pieces two lineups may share. Blank or high = off.

Max shared skill core (QB/RB/WR/TE)

Same idea across every non-defense spot.

Min unique players per lineup

Min players that must differ vs. every prior lineup. Higher = more diversity but harder to solve. 1 = only need 1 new player each time.

Lineups

What is this NFL DFS lineup optimizer?

A free NFL DFS optimizer for DraftKings, FanDuel and Yahoo — no signup, no paywall, no “3 free lineups” teaser. It solves a real mixed-integer program (the same math the paid tools use) to build a set of lineups that are individually strong and collectively different, because in large tournaments one good lineup is easy — twenty different good ones is the hard part.

How it works

Export the player list from DraftKings, FanDuel or Yahoo and upload it above.
Trim the pool: lock, exclude, or cap exposure on any player, and overwrite projections.
Set the rules — how many pass-catchers stack with your quarterback, whether to bring a player back from the other side of that game, per-team caps, and how different each lineup must be from the rest.
Generate. You get salary-cap-legal lineups in a CSV formatted for direct re-upload.

A worked example

DraftKings and FanDuel run the same nine-slot classic NFL roster — QB, two RB, three WR, TE, a FLEX, and a defense — under a $50,000 cap on DraftKings and $60,000 on FanDuel. Yahoo fills the same nine slots under a $200 cap, and requires players from at least three teams with no more than six from any one team. Under the hood that is a knapsack problem: maximize projected points subject to the cap and the position rules.

What makes NFL different from baseball is correlation. A quarterback and his receiver score the same touchdown twice, so stacking them is not a preference — it is a constraint you write into the model. Add a bring-back from the opposing team to catch a shootout, refuse to roster a defense against your own offense, and cap how often any one player appears across the set. The optimizer treats all of it as hard constraints, not suggestions.

Common questions

Is it really free? Yes — it is a working demo of optimization models I have built for 20+ years. No account, no lineup limit tricks.

Which sites does it support? DraftKings, FanDuel and Yahoo player exports, with upload-ready CSV output for each.

What about Showdown / single-game contests? Not yet — this is classic full-slate only.

Are the projections any good? Unless you upload your own, the tool uses the site's own number from your file — DraftKings' AvgPointsPerGame, FanDuel's and Yahoo's FPPG. That is a season average of actual fantasy points, not a forecast for this week: it knows nothing about the matchup or an injured teammate, and early in the season it rests on one or two games. Upload a projections CSV (or overwrite numbers in the list) and those replace it. The optimizer's job is squeezing the most out of whatever numbers you trust.

How do I use the Vegas lines? Load your file, then press Load Vegas lines in step 2. Each team gets an Impl number — the points Vegas expects it to score, from the game total and the spread. Sort the list by Impl to see the slate from the top down, then go to step 3 → Tier 2 → Vegas stack rules: Only stack teams implied ≥ means no quarterback (and so no stack) from a team below that number, and Only stack QBs whose game total ≥ does the same by game — pair it with a bring-back to build shootout stacks from both sides. Both boxes start blank, which means off. They never change the blue checkboxes, a team whose game has no line is never filtered, and if a number leaves no quarterback you get a message saying so.

What does Update injury list do? It checks every player on your slate against ESPN’s injury report. Players listed out, on IR or suspended are unchecked — tick them back if you disagree; questionable and doubtful players just get a badge. Use On/Off by status above the player list to switch a whole status on or off at once.

Do you have one for baseball? Yes — the MLB lineup optimizer works the same way, with batting-order stacking instead of quarterback stacking.

NFL Lineup Optimizer