Myth 1: "Decimal and American Odds Are Completely Different Systems"

Say a favorite is priced at 1.50 in decimal odds. That exact same probability shows up as -200 in American odds and as 1/2 in fractional odds. Same outcome, same payout, three different labels, not three different systems.

Once you see that, the three formats stop looking like separate languages and start looking like three accents describing the same underlying number.

Myth 2: "A Bigger Number Always Means a Bigger Underdog"

This one breaks the moment you switch formats. In decimal odds, a bigger number does mean a bigger underdog: 1.50 is a solid favorite, 5.00 is a significant underdog. In American odds, the rule flips depending on the sign. -200 is a heavy favorite, but a small positive number like +105 is barely an underdog at all, while a large positive number like +500 is a big one.

The size of the number only means something once you know which format you're reading and which sign, if any, is attached to it. Treating "bigger number" as a universal rule across formats is exactly how this myth causes real confusion, especially for anyone who learned one format first and assumes the same intuition transfers directly to another.

Decimal Odds, Explained

Decimal odds are the simplest format to calculate by hand, and the default on most regulated Philippine sportsbooks. Multiply your stake by the decimal number, and the result is your total return, stake included. At 1.50, a ₱100 stake returns ₱150 total, meaning ₱50 in profit.

Anything under 2.00 marks a favorite. Anything over 2.00 marks an underdog. Exactly 2.00 is an even-money bet: double your stake, no more, no less, the closest thing to a true coin flip you'll find priced on a sportsbook.

Try this math yourself by browsing today's matchups on UnliBets and converting a few real lines.

American Odds, Explained

American odds use a plus or minus sign in front of a number. Read it as a ratio, not a currency amount: a minus sign marks the favorite and tells you how many units you'd need to stake to profit 100 units. A plus sign marks the underdog and tells you how many units of profit a 100-unit stake would earn.

Scaled down to a ₱100 stake: at -200, you'd profit ₱50 (total return ₱150), the same result as the decimal example above.

Fractional Odds, Explained

Fractional odds are less common on Philippine platforms but occasionally show up on UK-facing sportsbooks. They're written as profit over stake. Read 1/2 as "you profit 1 unit for every 2 units you risk." On a ₱100 stake, that works out to the same ₱50 profit as the decimal and American examples above.

Myth 3: "Implied Probabilities From Both Sides Should Add to 100%"

On a true coin flip, fair decimal odds would be exactly 2.00 on both sides, and the implied probabilities would add to exactly 100%. Regulated sportsbooks don't price it that way. A common pricing like 1.95 on both sides of a matchup means each side has an implied probability of about 51.3% (1 divided by 1.95), and both sides added together come to roughly 103%, even though a true coin flip only adds up to 100%.

That gap, the built-in margin baked into the odds themselves, is often called the vig or the juice. It's also the same underlying mechanic that makes combining multiple bets into a parlay carry a higher house edge than a single straight bet, which we cover in our parlay betting guide.

Expecting both sides to add to exactly 100% isn't just a misunderstanding of the math. It's assuming the sportsbook prices matchups the way a fair coin flip would, when the entire business model depends on it not doing that. The overround, another name for that same extra percentage, is present on essentially every matchup, every sport, every platform.

Myth 4: "You Can't Get Another Format If a Sportsbook Only Shows One"

A sportsbook displaying decimal odds by default doesn't mean American or fractional odds don't exist for that same bet. They're always convertible using the formulas in the FAQ below. Some platforms even let you switch the display format in account settings, but even when they don't, the underlying number is the same regardless of which notation happens to be shown.

This myth tends to persist because most bettors only ever see one format on their preferred platform, so the other two feel abstract or theoretical rather than genuinely interchangeable. They're not abstract. They're the exact same number, written differently.

Myth 5: "Odds Never Change Once They're Posted"

Odds move as money comes in on one side, or as news breaks close to game time. A team opening at 1.50 might drift to 1.60 or tighten to 1.40 by the time the game actually starts, and none of that movement changes the reading rules covered above. It just means the specific number worth checking is the one showing right before you place the bet, not one you saw earlier.

Line movement itself carries information, even if it's not something to blindly follow. A number moving heavily toward one side usually means a large volume of bets landed there, not necessarily that the sportsbook has new information about the game itself. Reading the direction of movement is a separate skill from reading the odds format, and the two shouldn't be confused.

Myth 6: "A Plus Sign Means You Should Bet That Side"

A plus sign in American odds marks the underdog and shows the profit on a fixed stake. It says nothing about whether that underdog is actually a good pick for a given matchup. The sign is purely descriptive of the odds format, not a recommendation from the sportsbook about which side to take.

This myth causes real harm when it leads someone to bet an underdog purely because the plus sign made the payout look attractive, without any actual reason to believe that side is likely to win. The sign describes the odds. It doesn't evaluate the matchup for you.

Practice Converting: A Few More Examples

A heavy favorite might price at 1.25 decimal, which converts to -400 American (divide -100 by 0.25) and roughly 1/4 fractional. A closer matchup might price at 1.91 decimal, converting to -110 American and 10/11 fractional. A significant underdog on the road might sit at 3.50 decimal, converting to +250 American and 5/2 fractional.

Notice the pattern across all these examples: the closer a decimal number sits to 2.00, the closer the matchup is considered to be. The further it drifts from 2.00 in either direction, the more lopsided the perceived matchup, whether that's a heavy favorite below 1.30 or a big underdog above 3.00.

How Odds Notation Applies Across Bet Types

Everything covered so far uses a moneyline example, betting on who wins outright. The same three notation systems apply just as directly to a point spread or a total points bet. A spread bet is usually priced close to even odds on both sides regardless of how big the favorite is on the moneyline, since the sportsbook adjusts the point margin instead of the odds to balance the bet.

A total points bet works the same way: the odds format is identical, decimal, American, or fractional, only the underlying question changes from "who wins" to "will the combined score go over or under a number." Learning odds notation once covers every bet type, not just straight moneyline picks.

Same-Game Parlays and Odds Notation

Once you're combining more than one selection from the same game into a single ticket, a same-game parlay, the odds notation itself doesn't change. What changes is that the sportsbook has to account for correlation between your picks, since outcomes within one game often move together. The reading rules for decimal, American, and fractional odds stay identical regardless of how many legs are on the ticket.

A Quick Reference

• Decimal: Multiply your stake by the number for your total return, stake included.
• American: Negative numbers show stake needed to profit 100 units, positive numbers show profit on a 100-unit stake.
• Fractional: Read as profit over stake, so 1/2 means profit 1 unit per 2 units risked.

What Implied Probability Actually Tells You

Every odds number, in any format, secretly encodes a probability estimate. Decimal odds convert to implied probability with a simple formula: 1 divided by the decimal number, expressed as a percentage. A favorite at 1.50 decimal implies a probability of about 66.7%. That's the sportsbook's estimate of how likely that side is to win, before the vig gets added on top.

This matters because the implied probability is what you're actually comparing your own opinion against, not a certainty about what will happen. If your own estimate matches the implied number closely, the bet isn't offering much of an edge either way.

This is also where reading odds turns into something more useful than just decoding a number. The implied probability is a starting point for comparison, not a final verdict on whether a bet is worth making. Your own read on a matchup, based on injuries, recent form, or matchup-specific factors, is what actually gets compared against that baseline number, and that comparison is where genuine judgment comes into play.

Shopping for the Best Number

Once you can read and convert odds confidently, a natural next step is comparing the same matchup across different platforms before placing a bet. A favorite priced at 1.50 on one sportsbook might show 1.55 on another for the exact same outcome. That small gap compounds over a season of bets, the same way a small edge compounds in any repeated activity.

Neither price is wrong. Sportsbooks set their own lines independently, so small differences between platforms are normal rather than a sign that one of them made a pricing mistake. This only works once reading odds stops requiring conscious effort, since trying to compare three notation systems across multiple platforms while still mentally converting each one is slow and error-prone.

Common Mistakes That Fuel These Myths

• Assuming one format is inherently more honest than another. All three formats encode identical information.
• Comparing raw numbers across formats without converting first. A -200 and a 1.50 can describe the exact same bet.
• Treating implied probability as certainty. A 66.7% implied probability means the outcome is expected to happen more often than not, not that it's guaranteed.
• Reading an odds number you saw hours ago instead of the current one. Odds shift before a game starts.
• Assuming a plus sign is a recommendation. The sign only describes favorite or underdog status.