Keno Odds: The Worst House Edge on the Floor

Every game in the casino charges a tax. Blackjack takes about half a percent. The craps pass line, one and a half. Keno backs up a truck. It hands you a card, a crayon, and a dream about hitting all ten — and quietly pockets somewhere between 20 and 35 cents of every dollar you feed it. That is the worst keno house edge math you will find on any main floor, and it hides in plain sight: on a pay table that looks generous until you check it against the true odds.

This is part of Extra Credit, our casino-math series. Category: designed to lose — no skill, independent draws, and the steepest tax in the building.

How to read this game: expected value and the house edge

Keno is simple. You mark a set of numbers — a “spot” — and the casino draws 20 numbers out of 80. Match enough of yours and the pay table pays you. That’s the whole game: no dealer decisions, no skill, no strategy that touches the outcome.

So the only question that matters is the same one that prices every wager — its expected value. Add up each way the ticket can win, weight each by its probability, subtract your stake:

Here is the chance of catching exactly of your numbers, is the total return per $1 for that result, and the is the dollar you paid. A fair bet would land at . Keno’s pay tables are built so this sum comes out deeply negative — the house edge is just . Let’s watch it happen on the simplest possible ticket.

The jackpot is the bait

The 1-spot is honest about its robbery. The multi-spot tickets are where keno does its real work, because the true odds get astronomical and the payouts don’t come close to keeping up. The 10-spot is the poster child: catch all ten and win a headline jackpot. It sounds like a lottery ticket for a dollar. It is priced like one too — against you.

Whatever the ticket, the tax is the same

A real 10-spot ticket doesn’t only pay on all ten — it pays smaller amounts for catching 5, 6, 7, 8, or 9, and the full expected value blends all of those outcomes together. Grind through any honest keno pay table and the answer barely moves: the built-in edge lands around , and depending on the ticket and the casino it ranges from bad to worse.

Why you can’t beat it, long-term

Some casino games leave a crack for skill — card counting in blackjack is the famous one. Keno leaves none. Every draw is an independent pull of 20 balls from 80, and every number is equally likely on every game. There is nothing to read, nothing to time, nothing to count.

Read that as the death of every keno “system.” The draw has no memory. A number that has come up five games running is exactly as likely next game as one that hasn’t shown all night — the balls don’t know their own history. Those “hot number” and “cold number” boards the casino helpfully posts? Pure gambler’s fallacy, dressed up as data. Lucky numbers, birthdays, patterns on the card — none of it shifts a single probability.

And here’s the part that no lucky pick can fix: even if you knew the future, the pay table still shortchanges you. Keno’s edge doesn’t come from the draw being unpredictable — it comes from the casino paying winners a fraction of true odds by design. You can’t out-guess a game whose price is baked into the payout column. Chasing the 10-spot jackpot game after game isn’t a strategy; it’s chasing a jackpot, and the longer you chase, the more certainly the collects.

The one-line summary

Keno draws 20 of 80, pays every winning spot at a small fraction of its true odds, and so carries a house edge of roughly to — among the worst on the floor. A single number is a fair-ish to catch but gets paid like a robbery; hitting all ten is a million shot paid pennies on the fair dollar. Every draw is independent, so no lucky numbers, hot-number chart, or system moves the odds. The jackpot is the bait. The negative EV is the whole point.

The same expected-value math that prices a keno ticket prices a sportsbook line. See it work on the free +EV tool, or read how expected value finds an edge.

Watch it vanish

Six players, $25 a ticket, 1,000 draws, at keno’s brutal ~25% edge. The rare hit teases; the math is merciless. This is the fastest bleed on the floor.