Synthetic Hold Explained: The Hidden Tax on Every Bet

You know that -110 on both sides of a spread means the sportsbook takes a cut. But do you know exactly how much? And do you know that it varies wildly depending on what you bet?

The answer is something called "synthetic hold"—and understanding it is the difference between smart bettors and everyone else.

What Is Hold?

"Hold" is the percentage of money wagered that the sportsbook expects to keep. Think of it as the house edge, similar to the casino's advantage in blackjack or roulette.

In a perfectly fair market with no juice, you'd bet $100 to win $100 on a coin flip. But sportsbooks don't operate that way. They build in margin so they profit regardless of outcome.

That 4.55% is the theoretical hold on a standard -110/-110 market. It's what the book expects to keep from every dollar wagered on that market over time.

Visualizing the Hold

This is what a "fair" market looks like at standard juice. But not all markets are -110/-110.

Why Synthetic Hold Matters

Different bet types have different hold percentages. "Synthetic hold" is the calculated hold based on the actual odds offered—and it varies dramatically:

See the problem? That "fun" 4-leg parlay or "exciting" SGP has a house edge 4-6 times higher than a straight spread bet. You're paying a massive premium for the entertainment value.

How to Calculate Synthetic Hold

The formula is straightforward once you understand implied probability:

Step 1: Convert odds to implied probability

• -110 = 110 ÷ (110 + 100) = 52.38%
• +150 = 100 ÷ (150 + 100) = 40.00%

Step 2: Add both sides' implied probabilities

• If both sides are -110: 52.38% + 52.38% = 104.76%

Step 3: The amount over 100% is the hold

• 104.76% - 100% = 4.76% hold

Where the Hold Gets Ugly

Same Game Parlays

SGPs are priced by algorithms that add correlation adjustments—and those adjustments almost always favor the house. A "fair" SGP would give you better odds than you're getting. The house is taking 15-25% off the top.

Futures Markets

Add up the implied probabilities of every team to win the Super Bowl. You'll get 130-150%, meaning the book is holding 30-50% of the total pool. This is why sharps rarely bet futures.

Prop Bets

Player props often have wider juice (-115/-115 or -120/-110) because books have less confidence in their lines. You pay for that uncertainty through higher hold.

Live Betting

In-play markets move fast, and books protect themselves with wider spreads. That -110 pregame line might be -120/-110 live, adding 2%+ to the hold.

How Sharps Minimize Hold

Here's what smart bettors do:

1. Bet main markets. Spreads and totals have the tightest hold. Stick to them unless you have a specific edge elsewhere.
2. Line shop religiously. Finding -108 instead of -110 cuts your effective hold by 20%. That adds up.
3. Avoid parlays for entertainment. If you're going to parlay, know you're paying a premium for the payout structure.
4. Check the math on SGPs. Calculate what the legs would pay separately vs. what the SGP pays. The difference is your "entertainment tax."
5. Skip most futures. The hold is brutal, and your money is locked up for months. Not worth it unless you have a very strong opinion.

The Bottom Line

Synthetic hold is the invisible tax on every bet. At -110/-110, you're paying 4.55%. On a same game parlay, you might be paying 20%+. That difference is the gap between recreational betting and smart betting.

You can't eliminate the hold—sportsbooks need to make money. But you can minimize it by:

• Betting markets with the tightest hold (main lines)
• Shopping for the best odds across multiple books
• Understanding when you're paying extra for "entertainment" bets

Every percentage point of hold you save is money that stays in your pocket. Over hundreds of bets, that's the difference between losing and breaking even—or between breaking even and winning.