The Dupe Tax Calculator
You don't own your lineup — you share it with everyone else who built it. Enter your nine ownership percentages and see how many copies to expect, your odds of being unique, and what "winning" actually pays after the split. Runs the same duplication model as the SimSlate contest simulator.
Your lineup's projected ownership
Percent of the field rostering each player (from your projections source). Slots don't need to be exact — the math only sees the nine numbers.
Two identical scores. Two very different payouts.
In a GPP, ties split. If your lineup binks first place alongside seven copies of itself, you don't win the tournament — you win an eighth of it. That gap between the advertised prize and what a chalky build actually collects is the dupe tax, and almost nobody prices it in when they enter.
Duplication isn't bad luck. It's structural: the whole field reads the same projections and the same ownership reports, so popular players cluster into the same rosters. Every high-ownership player you add multiplies the odds that your exact nine-man combination already exists in someone else's hand.
Contest size is the whole game
The same lineup that's a near-lock to be unique in a 1,000-entry contest is duplicated dozens of times in the Milly Maker. That's why serious GPP players change how they build as fields get bigger — and why the curve above falls so fast. Uniqueness isn't a style choice; it's a function of field size, and the field is bigger than your gut says.
What this calculator can't see
This tool scores your lineup's popularity from joint ownership, calibrated against a real simulated field. What it can't tell you is whether the leverage is worth it — that depends on correlations inside your lineup, each player's actual range of outcomes, and how the whole payout curve (not just first place) behaves across 50,000 versions of the slate. That's the part that takes a full contest simulation: SimSlate builds the 50,000-lineup field you'll actually face, plays the tournament 50,000 times with correlated, non-normal player outcomes, applies this same duplication model to every field lineup, and ranks your builds by expected ROI — dupe tax included.
Questions people ask
Why do DFS lineups get duplicated?
Everyone builds from roughly the same projections and ownership signals, so popular players cluster together. The probability that someone else lands on your exact roster grows with each high-ownership player you add — and in a 150,000-entry contest, even a moderately chalky build is usually entered several times.
How many copies of a typical lineup are in the Milly Maker?
In SimSlate's simulated fields, a typical build shows up roughly 8–10 times in a 150,000-entry contest. Max-chalk builds can exceed 300 copies; genuine leverage builds have better-than-even odds of being one of a kind.
How is duplication calculated here?
The calculator scores a lineup's popularity from the joint ownership of all nine players — the same duplication model that runs inside SimSlate's contest simulator — calibrated against a real simulated 10,000-lineup field. It's an estimate (actual duplication varies by slate), but it's fitted to how real fields concentrate.
Does being unique earn me anything extra?
No. Uniqueness has no bonus — a unique lineup just keeps 100% of whatever it wins instead of splitting. That's exactly why the dupe tax matters: two lineups with the same score don't pay the same, and the chalkier one pays less.
Leverage notes, weekly.
One email a week during the season: where the field is over-concentrated, where the sim sees leverage, and the dupe traps to avoid — from real engine runs.