Understanding Betting Odds: A Beginner's Guide

If you're new to sports betting, odds can seem confusing at first. They're displayed in different formats, they carry mathematical meaning beyond simple "who's more likely to win," and understanding them is absolutely fundamental to making informed betting decisions. This guide explains everything you need to know.

What Do Betting Odds Represent?

At their core, betting odds serve two purposes:

• They indicate the probability (as estimated by the bookmaker) of an outcome occurring
• They determine your payout — how much you'll receive if your bet wins

Lower odds mean the bookmaker considers the outcome more likely. Higher odds mean it's considered less likely but pays more if it happens.

Decimal Odds

Decimal odds are the most straightforward format and are standard across most of continental Europe and increasingly popular in the UK. They represent the total return per £1 staked, including your original stake.

Total Return = Stake × Decimal Odds

Examples:

• Odds of 2.00 — Bet £10, get £20 back (£10 profit). This represents an even-money bet.
• Odds of 1.50 — Bet £10, get £15 back (£5 profit). The outcome is considered likely.
• Odds of 4.00 — Bet £10, get £40 back (£30 profit). The outcome is considered unlikely.

On BetWizard's predictions page, all odds are displayed in decimal format for clarity.

Fractional Odds

Fractional odds are the traditional UK format and you'll still see them widely used, especially on the high street and in horse racing. They show the profit relative to your stake.

• 5/1 (said as "five to one") — for every £1 staked, you profit £5 (total return £6)
• 1/2 (said as "one to two" or "odds on") — for every £2 staked, you profit £1 (total return £3)
• 6/4 (said as "six to four") — for every £4 staked, you profit £6 (total return £10)
• Evens or 1/1 — profit equals your stake

To convert fractional to decimal: divide the fraction and add 1. So 5/1 = 5 + 1 = 6.00 in decimal odds. And 1/2 = 0.5 + 1 = 1.50.

Moneyline Odds

Moneyline odds (also called American odds) are standard in the United States. They use positive and negative numbers:

• Positive (+200) — shows profit on a £100 stake. +200 means £200 profit from a £100 bet.
• Negative (-150) — shows how much you need to stake to profit £100. -150 means you bet £150 to profit £100.

UK bettors rarely need to use this format, but it's useful to understand if you follow American sports or use US-focused platforms.

Implied Probability: The Key Concept

This is where odds become really powerful for informed bettors. Every set of odds can be converted to an implied probability — the likelihood the bookmaker is assigning to that outcome.

Implied Probability = (1 ÷ Decimal Odds) × 100%

Examples:

• Odds of 2.00 → 50% implied probability
• Odds of 1.50 → 66.7% implied probability
• Odds of 3.00 → 33.3% implied probability
• Odds of 5.00 → 20% implied probability

Understanding implied probability is essential for value betting. If your analysis suggests an outcome has a 50% chance but the odds imply only 40%, you've found potential value.

The Bookmaker's Margin (Overround)

Here's something crucial that many beginners overlook: bookmaker odds don't add up to exactly 100%. They build in a margin (also called the overround or "vig") which is how they make their profit.

For example, in a two-outcome market:

• Team A: 1.90 (52.6% implied probability)
• Team B: 1.90 (52.6% implied probability)
• Total: 105.2% — the 5.2% overround is the bookmaker's margin

In a perfectly fair market with no margin, both sides would be offered at 2.00 (50% each, totalling 100%). The margin means bettors are always paying slightly over the fair price.

This is why finding value — where your estimated probability exceeds the implied probability — is so important. You need to overcome the bookmaker's built-in advantage.

How Odds Move

Odds aren't fixed. They change constantly based on:

• Betting volume — if lots of money comes in on one side, the bookmaker shortens those odds
• News and information — injury announcements, team selections, and weather conditions all cause odds movements
• Market forces — bookmakers adjust to stay competitive with each other

The closing odds (the final price just before an event starts) are generally considered the most accurate reflection of true probabilities, as they incorporate the maximum amount of information.

Practical Tips for Beginners

• Always calculate implied probability before placing a bet — know what the odds are telling you
• Compare odds across bookmakers — different bookmakers offer different prices. Always get the best available odds.
• Use decimal odds for calculations — they're the simplest format for maths
• Understand that lower odds ≠ safer bets — a 1.10 favourite can still lose, and you risk a lot for very little profit
• Start with our free predictions — BetWizard's AI predictions show you odds, confidence levels, and edge percentages to help you learn

Understanding odds is the foundation of informed sports betting. Once you're comfortable with these concepts, you'll be able to evaluate predictions and betting opportunities much more critically.