Learn how craps Buy Bets work, how the 5% vig is calculated, and why buying the 4 and 10 dramatically lowers the house edge.
Last updated:Whether you are standing at a noisy Las Vegas table or tapping away on a US betting app, the goal is the same: cut down the house edge.
Standard Place Bets let you put money straight on the 4, 5, 6, 8, 9, or 10, but the casino shorts your payout on the outside numbers. That is why Buy Bets exist. Once you see how the math works and how casinos take their cut, you will never play the 4 and 10 as regular Place Bets again – it’s one of several ways to fine-tune a Place Bet covered in our craps section.
Key Takeaways: Craps Buy Bets
- Buy Bet Mechanics: Paying a 5% commission (vig) allows you to receive True Odds payouts instead of reduced standard Place Bet rates.
- The 4 and 10 Advantage: Buying the 4 or 10 pays 2:1 and cuts the house edge from 6.67% down to 4.76%, or all the way to 1.67% when the vig is charged only on wins.
- Avoid Buying Inside Numbers: Purchasing the 5, 6, 8, or 9 is mathematically disadvantageous because the 5% fee makes the house edge worse than basic Place Bets.
- Bet in $20 Increments: Wagers should be placed in $20 increments to ensure a clean $1 vig and prevent paying disproportionate house fees on uneven amounts.
What Is a Buy Bet and How Does the Vig Work?
A Buy Bet works just like a Place Bet, with one major twist. You pay the casino a small fee, called the vigorish or “vig”, and in return, they pay you true mathematical odds instead of the standard stripped-down table rates. In US casinos, that fee is almost always 5%.
To keep the math clean and avoid dealing with loose change, the house charges $1 for every $20 you put down. Bet $20, pay a $1 vig.
Online, the software either takes that dollar right off your balance when you drop the chips or snags it from your profit after you win. The second option is much better, and plenty of modern apps work that way.
Place Bets vs. Buy Bets on 4 and 10
The difference on the outside numbers is night and day. Look at what happens on a basic $20 wager:
- Put $20 on a standard Place Bet on the 4 or 10. It pays 9:5. If your number rolls, you walk away with $36 in profit, handing the casino a rough 6.67% edge.
- Now buy that same number for $20. The casino pays you True Odds of 2:1. That means you win $40 right out of the gate. Hand back the $1 vig, and you still pocket $39 clean.
That extra three bucks might not sound huge on one roll, but it instantly drops the house edge from 6.67% down to 4.76%.
Even better, if your online platform only charges the vig on wins, that casino advantage collapses down to just 1.67%. It is a massive difference over an entire session.
Never Buy the 5, 6, 8, or 9
Buying the 4 and 10 is smart play. Buying the inside numbers is just throwing money away.
Place Bets on the 6 and 8 already pay 7:6, leaving the casino with a tiny 1.52% edge. Place Bets on the 5 and 9 pay 7:5, sitting at a 4.00% edge.
If you try to buy the 6 or 8 at True Odds (6:5) and pay a 5% vig on top, the math actually gets worse. The fee eats up any gain and pushes the casino’s advantage higher than the standard bet. The exact same trap applies to the 5 and 9.
Keep the rule simple: Place the 5, 6, 8, and 9, but always Buy the 4 and 10 in clean $20 steps.
Author:
Lucas Portela
Owner, BoldGambler • Avanhandava/SP
Oddsmaker, affiliate and content creator in the iGaming industry.