How much does a player prop actually cost you?
On one night of our board, across every book quoting both sides of a line, the overround on player props ran from 5.4% at the cheapest book to 11.4% at the widest. A standard -110 side charges 4.76%. So the received wisdom is right: the cheapest prop book on that slate was still more expensive than an ordinary point spread, and the widest was nearly two and a half times it.
“Props are high vig” is the most repeated sentence in prop betting and almost nobody attaches a number to it. The reason is boring: you cannot get the number from a screenshot of one price. You need both sides of the same line from the same book, across enough lines to be worth saying, and most people writing about it do not have a board.
We have one. Here is the number.
What it costs, against something you already know
A standard point spread at -110 on both sides charges 4.76%. That is the reference point almost every bettor already has a feel for.
On our board for the 12 September 2026 slate:
| Overround | |
|---|---|
| Standard -110 / -110 side | 4.76% |
| Cheapest book on props that night | 5.40% |
| Widest book on props that night | 11.36% |
So the received wisdom is correct and now it has a size. The cheapest prop pricing we measured was still more expensive than an ordinary spread. The widest was close to two and a half times it.
How this was measured, and why it is not the usual number
The overround is one book’s margin on its own two prices. It is computed one way:
implied(over) + implied(under) - 100
Both prices, same book, same line. We kept every case on the slate where that was available, which came to 6,213 player lines, and computed it on each one. The figures above are per-book medians over those lines.
This is worth separating from a number that looks like it and is not. A lot of “book comparison” work, including a table elsewhere in our own notes, scores each book against a consensus fair built from the other books on that row. That measures whether a book is priced better or worse than its peers. It is a useful number and it is not the overround, because it depends entirely on which peers happened to quote that row. Two books measured that way are being held to different yardsticks. The calculation above needs no peers at all: it is one book’s own two prices, so it is the same question asked of every book.
What we will and will not say about the ranking
We will name the two ends. NoVig cheapest at 5.40%, Fliff widest at 11.36%, on that slate.
We will not rank the books in between, and the reason is a test rather than modesty. Books hang different markets: on that night FanDuel priced seven, Fliff nineteen. Thin markets carry more margin, so a book that offers only main lines looks cheaper than it is being. We recomputed every book on only the markets all of them quoted, and two of the middle books swapped places on a move of a third of a point. The two ends survived that test and got further apart. The middle did not survive it, so publishing a five book ladder would be reporting noise as a finding.
And we left prediction markets out of the range. Polymarket’s figure on that board was far wider than any sportsbook’s, on around a hundred rows. It is a different mechanism and putting it inside a sentence about what sportsbooks charge would misdescribe what it is.
It is one night. Book pricing moves with the slate, and we would rather say one night than imply a season.
The finding: breadth is not free
Fliff hangs both sides on more markets than any other book on that board, nineteen of them, joint widest overall at twenty alongside DraftKings and Hard Rock Bet. It also carries the widest overround we measured.
That is not a coincidence in your favour. A long menu of unusual props is a long menu of thinly priced props. The market you can only find in one app is, reliably, the market that app charges the most to offer.
What the number does and does not buy you
It gives you a bar. On an evenly priced line, an overround of V means each side is asking you to be right (100 + V) / 200 of the time: about 52.7% at the cheap end and about 55.7% at the wide end. A flat 50% record returns V / (100 + V) as a loss, which is 5.1% of stake at one end and 10.2% at the other. That arithmetic is worked through in why your player props keep losing.
It does not tell you that you clear that bar. This page makes no claim about our own results: the pick record is being restarted as it goes public, so there is nothing here to point at yet.
What it does change is a decision you make before you look at any stat. Between the cheapest and the widest book on that board there were six points of margin. That is larger than most of the edges people spend their evenings hunting.
Do it on any price yourself
The calculation is small enough to do by hand and faster with a form. Put both sides of a prop into the no vig calculator and it returns the overround and what each side is worth with the margin stripped out.
If the concept is the part you want rather than the number, why -110 is not a coin flip is the explanation without a measurement attached. This page is the measurement.
The Lab board carries the fair alongside the price on every prop we track, so the comparison is already done before you take the bet.
Numbers on this page come from our own board for the 12 September 2026 slate, pulled the evening before, 6,213 player lines where a single book quoted both sides. One night. No sportsbook was contacted and there are no affiliate links on this page.
Quick answers
How much vig is on player props?
On one night of our board, 6,213 player lines where a single book quoted both sides, the overround ran from 5.4% to 11.4% depending on the book. A standard -110 point spread charges 4.76% for comparison.
Are player props higher vig than spreads?
Yes, on the night we measured. Every book on that board charged more on props than the 4.76% a standard -110 side charges, and the widest charged nearly two and a half times it.
How do you calculate the vig on a prop?
Convert both sides to implied probability and add them. The amount over 100% is the overround. You need both prices from the same book: one side on its own tells you nothing about the margin.
Which book has the lowest vig on props?
Of the books on our board that night, NoVig was cheapest at 5.40% and Fliff widest at 11.36%. The books in between sat within about half a point of each other and reordered when we held the market set constant, so we do not publish a ranking of them.
Is the vig the same on every prop?
No. Thin markets carry more than main lines, which is why a book offering a wide menu of unusual props tends to show a wider average. Books also differ in which markets they hang, so any across-the-board comparison carries that caveat.
Want tonight's board?
The Lab prices every player prop on the slate, shows the form and the matchup behind each line, and posts a short card before first pitch. Every pick is graded in public afterwards, win or lose. It is free and there is nothing to sign up for.