How the Hold/Vig Calculator Works
This calculator helps you understand the "vigorish" (also known as "vig" or "juice") or "hold" that a bookmaker builds into their betting odds. In simple terms, it's the commission or profit margin that the bookmaker expects to make from a betting market, regardless of the outcome.
The core principle is converting the odds for each possible outcome into an "implied probability." If a market were perfectly fair (with no bookmaker's edge), the sum of the implied probabilities for all outcomes would be exactly 100%. However, in real-world betting, this sum is almost always greater than 100%. The amount by which it exceeds 100% is the bookmaker's hold.
Here's how it works:
- Odds Input: You enter the odds for each possible outcome of an event (e.g., Team A wins, Team B wins, Draw). You can choose between American, Decimal, or Fractional odds formats.
- Implied Probability Calculation: For each outcome, the calculator converts the odds into an implied probability. For example, Decimal odds of 2.00 imply a 50% probability (1/2.00).
- Total Implied Probability: The calculator sums up all the individual implied probabilities.
- Bookmaker's Hold/Vig: This is derived from the total implied probability. If the total is 105%, the bookmaker's hold is 5%. This means that for every $100 wagered across all outcomes, the bookmaker expects to keep $5.
Why Gamblers Use It:
- Identifying Value: By knowing the vig, a sharp bettor can better assess whether the odds offered represent true value, or if the bookmaker's margin is too high.
- Comparing Bookmakers: Different bookmakers might offer different odds for the same event. This calculator allows gamblers to compare the vig across various sportsbooks to find the most favorable lines (those with the lowest vig).
- Arbitrage Opportunities: In rare cases, if the combined implied probabilities from different bookmakers for all outcomes sum to *less* than 100%, it indicates an "arbitrage" opportunity. This means a bettor can place bets on all outcomes with different bookmakers and guarantee a profit regardless of the result.
- Understanding the Market: It provides insight into how much the bookmaker is charging for their service and helps gamblers make more informed decisions.