Implied Probability and Hold

Implied probability is the chance an outcome would need to have for the odds to be fair.

Hold is the sportsbook’s built-in margin.

Put simply: odds are prices, implied probability turns those prices into chances, and hold is where the book hides its edge.

How to calculate implied probability

With decimal odds, the formula is simple:

So if the odds are 2.00:

• 1 ÷ 2.00 = 0.50
• 0.50 = 50%

Odds of 2.00 imply a 50% chance.

A few quick examples

Where hold comes in

In a perfectly fair two-outcome market, both sides should add up to 100%.

But sportsbooks do not usually offer perfectly fair prices.

They build in a margin.

Imagine a coin toss.

Fair odds would be 2.00 on heads and 2.00 on tails.

• Heads at 2.00 = 50%
• Tails at 2.00 = 50%
• Total = 100%

But a sportsbook might offer 1.91 on both sides.

• Heads at 1.91 = 52.36%
• Tails at 1.91 = 52.36%
• Total = 104.72%

That extra 4.72% is the hold.

Why this matters for +EV

+EV betting is about finding prices that are better than they should be.

But before we can know whether a price is good, we need to understand what chance the market is implying.

That is why implied probability matters.

And because the sportsbook has margin built in, we often need to remove the hold before we can estimate the fair price.

That process is called de-vigging.

How Edge Hunters handles it

You do not need to sit there converting every price by hand.

Edge Hunters does the maths for you. It turns odds into probabilities, accounts for the book’s margin, and helps surface prices where the edge is actually worth caring about.

The key takeaway

Odds are not just payouts.

They are probabilities in disguise.

Once you understand that, +EV betting starts to make a lot more sense.

Next up: What is de-vigging? How to remove the sportsbook’s margin and find the fair price.