Implied Odds vs True Odds
Implied odds are the win chance baked into a price; true odds are the real probability. The gap between them is your edge, with worked examples.
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Implied odds are the win percentage baked into a betting price; true odds are the real probability of the event. Two claims about one outcome — one made by the market, one settled by reality — and the space between them is your entire edge. When the true probability sits above what the price implies, you have value; when it sits below, you’re being milked.
(One naming trap up front: in betting, “implied odds” means the probability a price implies — the sense used here. In poker it means the extra chips you win on later streets after a draw connects; see implied odds explained. Don’t blend the two.)
The implied side
Implied odds are just implied probability, the win chance read straight off a price. For decimal odds it’s one division:
implied probability = 1 ÷ decimal
A decimal price of 2.10 implies 1 ÷ 2.10 = 47.6%. That’s the market’s opinion — no more, no less.
The true side
True odds are the actual probability, stripped of any house margin. A fair coin has true odds of exactly 50% — even money, +100, decimal 2.00. Nobody knows an event’s true odds precisely, but building a sharp estimate is the whole job, because it’s the only thing you can hold the price up against.
The vig forces a gap
Here’s why implied and true odds rarely line up. Take a genuine 50/50 event: fair odds are +100 a side, and two 50% figures sum to a clean 100%. But no book prices a coin flip at even money — it shades both sides to -110, so each implies 110 ÷ 210 = 52.4%. Add them: 52.4% + 52.4% = 104.8%. That 4.8% surplus can’t be real probability; it’s the vig, the built-in margin. Divide each side by the total to recover the market’s honest estimate: 52.4% ÷ 104.8% = 50%, the fair coin restored. So raw implied odds sit above the true odds the market actually believes — always inflated by the margin.
| Event | True (fair) | Priced | Implied | Devigged |
|---|---|---|---|---|
| Fair coin | 50% / +100 | -110 each | 52.4% | 50% |
| Underdog | 40% / +150 | +150 | 40% | ~38% |
| Favorite | 66.7% / -200 | -200 | 66.7% | ~63% |
The devigged column is the market’s best guess at the true odds. Your job is to decide whether your estimate beats the implied number — that comparison is the edge.
Putting a number on the edge
Suppose you’ve studied a matchup and your honest read of the true probability is 55%. A book offers even money, +100 (decimal 2.00), so implied odds are 1 ÷ 2.00 = 50% — the price underrates the outcome by five points. Stake 100 units:
EV = (0.55 × 100) − (0.45 × 100) = +10 units
Ten units of profit per 100 staked, purely because your 55% read beat the implied 50%. Flip it: at a 45% true estimate on the same +100, EV is −10 — now you’d be backing an outcome the price overrated. Same price, opposite result, decided entirely by the true-versus-implied gap.
It’s the poker math too
At the felt, your pot odds are an implied probability — the price of a call converts into the minimum win rate you need. A half-pot bet lays 3-to-1, an implied 25%. Your equity is your estimate of the true probability you win. You call when equity beats that implied number — the identical “true beats implied” test a bettor runs on a line. The vocabulary swaps; the comparison doesn’t.
So the practical drill is short: build a true-odds estimate, devig the price, and bet only when your number clears it. The most common leaks are treating the implied figure as fact, forgetting to devig a single side, or wagering with no true-odds read at all — you can’t spot a bargain if you can’t name the real probability. Sharpen the estimate through implied probability and equity, then carry the same instinct to the Hold’em tables and the poker odds & math hub.