Craps Buy Bet Vig Rules: The Brutal Truth About Commission Structures
The house doesn't beat you on the odds—it beats you on the commission, and every craps player who ignores the vig on buy bets is bleeding money without even realizing it. I've watched countless players celebrate a $100 buy bet on the 4 or 10 like they cracked the code, completely blind to the fact that the casino already clipped them before the dice even left the shooter's hand. The craps buy bet vig rules are where the real war is fought, and if you don't understand the commission mechanics cold, you're just another mark at the table.
How the Commission Actually Gets Calculated
Here's the raw mechanics: a buy bet lets you wager on 4, 5, 6, 8, 9, or 10 with true odds payout instead of the watered-down place bet odds. Sounds great on paper. But the house charges a 5% commission on the wager amount, and that commission is typically collected upfront when you make the bet. On a $20 buy bet, you're handing over $1 immediately. The critical rule most players miss is the rounding threshold—casinos round the vig to the nearest dollar, and some floor supervisors round up aggressively. A $25 buy bet at 5% hits $1.25, which gets rounded to $2 in plenty of houses. That rounding mechanic alone can push the effective house edge on a buy bet from around 1.5% to well over 2% depending on your denomination. You need to test your table's rounding behavior before you commit real money. 🎲
The $20 Threshold and Why It Matters
If you're buying the 4 or 10 for anything less than $20, stop immediately—you are torching your own bankroll. The craps commission bet guide position that most sharp players follow is dead simple: buy bets only make mathematical sense at $20 and above, because the flat 5% commission is a fixed cost that gets diluted as your wager grows. At $20, the commission is $1, and the house edge on the 4 or 10 lands around 2.44%. At $25 with a $2 rounded vig, that edge climbs to nearly 2.9%—worse than a $25 place bet on the 6 or 8, which sits at 1.52%. The sweet spot sits at $20, $40, and $100 increments where the 5% commission stays clean at $1, $2, and $5. Break those increments and the rounding tax eats you alive. The profit variance between a disciplined $20 buyer and a sloppy $25 buyer over a few hundred roll cycles is staggering. 📊
Vig Collection Timing and the Pressure Play
Some houses collect the vig only on a win—often called "pay the vig on the win" or "vig on the back end." This is a massive structural difference and it shifts the effective house edge considerably. When the commission is collected after a winning roll, your bankroll survives longer during cold streaks because you're not shelling out $1 on every single come-out. But don't get comfortable: the house compensates by sometimes charging slightly higher rates or by structuring the dealer's payout handling to your disadvantage on pressed bets. Always confirm whether your table collects commission upfront or on the win before you scale up your wager. The dealers will tell you if you ask directly, and any pit boss who hesitates on that answer is running a structure you need to walk away from. 🎯
Buy Betting the 5, 6, 8, and 9
The 4 and 10 are the classic buy bets—true odds of 2:1 versus place odds of 9:5, so the commission is clearly worth it at the right denomination. But the 5 and 9 are where the math gets nastier. True odds pay 3:2 versus place odds of 7:5. On a $20 buy of the 5, you risk $1 commission to gain the difference between $30 and $28—a mere $2 edge. That's a razor-thin margin that evaporates entirely if the vig rounds up to $2. The 6 and 8 are even worse: true odds of 6:5 versus place odds of 7:6, and the gap on a $20 wager is so small that the commission almost never justifies the buy. My hard position: buy the 4 and 10, place the 6 and 8, and only buy the 5 and 9 at $40 or higher where the true-odds payout gap widens enough to absorb the flat commission. 🎰
Commission Tax on Pressed and Stacked Bets
Every time you press a buy bet, the commission resets. That means a player who presses a $20 buy on the 4 up to $40 has now paid $1 on the first bet and another $2 on the pressed amount—$3 total commission on $40 in action, which is a 7.5% effective commission load if you count the original wager. This is the silent killer of aggressive press strategies. The disciplined play is to size your initial buy bet at the final amount you intend to press to, and place the intermediate amounts rather than churning commissions. Watch the dealers closely too—some will auto-collect vig on any buy bet change without announcing it, and if you're not tracking every dollar of that commission flow, you'll find your stack short at the end of the session. The commission is the casino's steady drip, and the only defense is knowing the exact denomination breakpoints cold.