How to Calculate the Hold (House Edge) Across Multiple Sportsbooks: Step-by-Step Guide for 2026
To calculate the hold, or house edge, across multiple sportsbooks, convert each book’s odds to implied probabilities, sum them for each outcome, and compare the totals to find which sportsbook offers the lowest hold. This method reveals which book is taking less of a cut and helps identify where the value lies for any given market in 2026.
What Is Hold (House Edge) in Sports Betting?
Hold, often called the “house edge” or “overround,” is the built-in percentage advantage that a sportsbook has over bettors. It represents the portion of the betting pool that the sportsbook expects to keep—regardless of the event outcome—due to setting the odds in a way that the total implied probability exceeds 100%.
Why Compare Hold Across Multiple Sportsbooks?
Not all sportsbooks price markets the same way. Some may build in a higher hold, reducing your expected value even before fees or taxes. Comparing the hold across books helps you:
- Spot which book offers better theoretical value for a given event.
- Identify opportunities where the total implied probability approaches—or even dips below—100%, sometimes opening up arbitrage opportunities.
- Understand the real cost of betting at each venue, beyond just the odds themselves.
ArbMonster measures and ranks the real vig of 20+ US sportsbooks every 15 minutes, letting you see which books are sharpest at a glance.
The Math: Calculating Hold for Any Set of Odds
Let’s walk through the calculation with real-ish numbers. Suppose three sportsbooks offer the following American odds on a two-outcome NBA game (Team A vs Team B):
| Sportsbook | Team A | Team B |
|---|---|---|
| Book 1 | -110 | -110 |
| Book 2 | -105 | -115 |
| Book 3 | +100 | -120 |
Step 1: Convert Each Outcome to Implied Probability
Use this formula for American odds:
- For negative odds (e.g., -110):
$\text{Implied Probability} = \frac{|\text{Odds}|}{|\text{Odds}| + 100}$ - For positive odds (e.g., +100):
$\text{Implied Probability} = \frac{100}{\text{Odds} + 100}$
Book 1 (-110/-110)
- Team A: $\frac{110}{110 + 100} = 0.5238$ (52.38%)
- Team B: $\frac{110}{110 + 100} = 0.5238$ (52.38%)
- Total: $0.5238 + 0.5238 = 1.0476$ (104.76%)
- Hold: $4.76%$
Book 2 (-105/-115)
- Team A: $\frac{105}{105 + 100} = 0.5122$ (51.22%)
- Team B: $\frac{115}{115 + 100} = 0.5349$ (53.49%)
- Total: $0.5122 + 0.5349 = 1.0471$ (104.71%)
- Hold: $4.71%$
Book 3 (+100/-120)
- Team A: $\frac{100}{100 + 100} = 0.5000$ (50.00%)
- Team B: $\frac{120}{120 + 100} = 0.5455$ (54.55%)
- Total: $0.5000 + 0.5455 = 1.0455$ (104.55%)
- Hold: $4.55%$
Step 2: Rank Sportsbooks by Hold
| Sportsbook | Hold |
|---|---|
| Book 3 | 4.55% |
| Book 2 | 4.71% |
| Book 1 | 4.76% |
Book 3 offers the lowest hold in this market. If your only goal is to minimize the house edge, you’d prefer Book 3—assuming limits, availability, and other factors are similar.
What About Multi-Outcome or 3-Way Markets?
The same process applies. Let’s see a soccer match (win/draw/lose):
| Sportsbook | Home Win | Draw | Away Win |
|---|---|---|---|
| Book A | +160 | +210 | +170 |
Convert to implied probabilities:
- Home Win: $\frac{100}{160+100} = 0.3846$ (38.46%)
- Draw: $\frac{100}{210+100} = 0.3226$ (32.26%)
- Away Win: $\frac{100}{170+100} = 0.3704$ (37.04%)
- Total: $0.3846 + 0.3226 + 0.3704 = 1.0776$ (107.76%)
- Hold: $7.76%$
You can repeat this for any sportsbook, then compare.
Why Does Hold Matter for Arbitrage and Value?
A lower hold means the sportsbook is taking less of a cut, which improves the odds you’re offered. In some rare cases, if you combine the best odds from multiple books for each outcome, the total implied probability can be less than 100%—creating an arbitrage opportunity (mathematically, not always practically fillable).
ArbMonster’s live dashboard automates this process, calculating actual hold for each book, market, and opportunity—including all fees and order book depth—so you can focus on actionable edges.
Worked Example: Finding the Best Value in 2026
Suppose you want to bet on the MLB World Series winner. Three books offer these odds:
| Team | Book X | Book Y | Book Z |
|---|---|---|---|
| Dodgers | +350 | +375 | +340 |
| Yankees | +500 | +480 | +510 |
| Astros | +600 | +610 | +590 |
| Mariners | +700 | +680 | +720 |
| Braves | +400 | +410 | +430 |
First, convert each book’s odds to implied probability for all teams, sum them, and calculate the hold. Then, construct a “no-vig” line by taking the best odds from each row (team), recalculating the sum, and seeing if an arbitrage is possible. In practice, the lowest hold is usually where the best value lies.
Key Takeaways
- Hold (house edge) is calculated by converting odds to implied probabilities and summing them; anything above 100% is the sportsbook’s margin.
- Comparing hold across sportsbooks reveals which ones offer better theoretical value for the same event.
- Lower hold means less money taken by the book; sometimes, combining the best odds from each book can create an arbitrage opportunity.
- ArbMonster automates live hold calculations across 20+ books for every major market, net of fees and depth.
- Always confirm that the odds and limits are available to you and consider all venue restrictions.
FAQ
Q: What is the difference between hold and vig?
Hold and vig are closely related terms. "Vig" (short for vigorish) is the sportsbook’s commission built into the odds, while "hold" is the percentage of money the sportsbook expects to keep after settling bets. Both are calculated by summing implied probabilities and subtracting 100%.
Q: Can the hold ever be negative?
Yes, in rare cases when you combine the best odds from multiple books for each outcome, the total implied probability can dip below 100%. This means there's a theoretical arbitrage opportunity, but practical factors like limits, timing, and availability may prevent execution.
Q: How do I calculate hold for decimal odds?
For decimal odds, the implied probability is $1/\text{decimal odds}$. Sum the probabilities for all outcomes and subtract 1 (or 100%) to get the hold. ArbMonster offers a vig calculator for decimal odds.
Q: Does hold include prediction market fees like Kalshi or Polymarket?
Standard hold calculations for sportsbooks do not include external fees. However, ArbMonster includes all trading fees (like Kalshi's 7% taker fee or Polymarket's 4–7% taker fee by category) when showing net opportunities across venues. You can view full fee schedules here.
ArbMonster is a data service. Nothing here is financial or betting advice; markets carry risk, venues have age and jurisdiction restrictions, and you are responsible for verifying everything before acting.