Parlay Calculator

Understanding Parlay Bets:

A parlay (called an "accumulator" or "acca" in the UK, "multi" in Australia) is a single bet that links together two or more individual wagers for a higher payout. The catch? Every single selection must win for the parlay to pay out. If even one leg loses, the entire parlay loses.

How Parlay Odds Are Calculated:

When you combine bets into a parlay, the odds multiply together:

Parlay Calculation:

• Combined Decimal Odds: 1.909 x 1.667 x 2.000 = 6.37
• $100 Bet Payout: $100 x 6.37 = $637
• Profit: $537

Parlay Payout Table (Standard -110 Odds):

Note: Sportsbooks typically pay less than "true odds" on parlays—this is how they profit.

Why Sportsbooks Love Parlays:

Parlays generate massive profits for sportsbooks because:

1. The house edge increases with each leg added
2. Bettors overestimate their ability to pick multiple winners
3. The big payout potential attracts more action
4. One wrong pick negates any winning selections

The Math That Most Bettors Ignore:

The allure of parlay payouts blinds many bettors to the actual probability of winning. Here's the reality:

Implied Probability by Number of Legs (at -110 odds each):

Converting Odds to Implied Probability:

American Odds to Probability:

• Favorites (-): Probability = |Odds| / (|Odds| + 100)
• Example: -150 = 150 / (150 + 100) = 60%
• Underdogs (+): Probability = 100 / (Odds + 100)
• Example: +200 = 100 / (200 + 100) = 33.3%

Decimal Odds to Probability:

• Probability = 1 / Decimal Odds
• Example: 2.50 = 1 / 2.50 = 40%

Example: 4-Leg Parlay Probability:

Combined Probability: 0.5238 x 0.60 x 0.50 x 0.5455 = 8.58%

This means you need to win roughly 1 in 12 attempts just to break even, yet sportsbooks pay at rates assuming 1 in 10 wins.

The Vig Multiplies:

Each leg carries the standard ~4.5% house edge, but this compounds:

• 2-leg parlay: ~10% house edge
• 4-leg parlay: ~13% house edge
• 6-leg parlay: ~14% house edge
• 10-leg parlay: ~15%+ house edge

Standard Parlay:

All legs must win. One loss = entire bet loses.

• Pros: Highest potential payout
• Cons: Highest risk, one loss busts all

Round Robin:

A round robin creates multiple smaller parlays from your selections. For example, a 3-team round robin creates three 2-team parlays.

Example: 3-Team Round Robin ($10 per parlay = $30 total)

Round robins provide insurance against one bad pick but require more stake money.

Teaser:

A teaser adjusts the point spread in your favor for every leg, but at reduced odds.

6-Point NFL Teaser Example:

Standard 2-team 6-point NFL teaser pays -110 instead of the ~+264 a regular parlay would pay.

Pleaser (Reverse Teaser):

Moves the line against you for much higher payouts. Extremely risky.

Same Game Parlay (SGP):

Combines multiple bets from the same game (player props, totals, spreads). Sportsbooks adjust odds to account for correlation between outcomes.

Parlay Cards:

Fixed-odds parlay cards with predetermined payouts, common in Nevada casinos. Usually offer worse odds than betting board parlays.

Progressive Parlay:

Allows 1-2 losses and still pays (at reduced rate). Less common but available at some sportsbooks.

The Case Against Parlays:

Most professional sports bettors avoid parlays entirely. Here's why:

1. Compounding House Edge: Each leg adds to the sportsbook's advantage
2. Difficult to Beat Long-Term: Even if you're a winning bettor on individual games, parlays amplify variance
3. False Value: The big payouts feel like value but mathematically aren't
4. One Bad Leg Erases Everything: A 4-0 run means nothing if leg 5 loses

When Parlays Make Mathematical Sense:

There are limited scenarios where parlays can be +EV (positive expected value):

1. Correlated Parlays: When outcomes are related (running back TDs correlate with team winning). Most sportsbooks restrict these.

2. Odds Boosts: Promotional enhanced parlay odds that exceed true odds.

3. Arbitrage Situations: Using parlay odds from one book against straight bets at others (rare).

4. Recreational Entertainment: If your goal is entertainment with small stakes, parlays maximize excitement per dollar.

Bankroll Management for Parlays:

The Smart Approach:

If you enjoy parlays despite the math, consider:

• Keep parlay stakes to under 5% of your total betting bankroll
• Limit to 2-4 legs maximum
• Focus on legs you have genuine conviction on
• Use round robins for more protection
• Never chase losses with bigger parlays
• Track your parlay results separately to see true performance

American Odds (Moneyline Odds):

The standard format in US sportsbooks. Based on $100 wagers.

Favorites (Negative): How much to bet to win $100

• -150 means bet $150 to win $100 (total return: $250)
• -200 means bet $200 to win $100 (total return: $300)

Underdogs (Positive): How much you win on a $100 bet

• +150 means win $150 on a $100 bet (total return: $250)
• +300 means win $300 on a $100 bet (total return: $400)

Decimal Odds:

Standard in Europe, Australia, and Canada. Shows total return per $1 wagered.

Fractional Odds:

Traditional UK format, common for horse racing.

Conversion Formulas:

American to Decimal:

• Positive: (American / 100) + 1
• Negative: (100 / |American|) + 1

Decimal to American:

• If Decimal >= 2.00: (Decimal - 1) x 100 = Positive American
• If Decimal < 2.00: -100 / (Decimal - 1) = Negative American

Fractional to Decimal:

• (Numerator / Denominator) + 1

For more detailed odds conversions, use our Betting Odds Calculator.

What Are Same Game Parlays?

Same Game Parlays allow you to combine multiple bets from a single game into one parlay. Previously, sportsbooks didn't allow this because outcomes within a game are often correlated.

Common SGP Combinations:

How Sportsbooks Price SGPs:

Books use proprietary algorithms to adjust odds based on correlation:

Example: Regular Parlay vs. SGP

Notice the SGP pays less because the outcomes correlate—if Kansas City wins big, the over is more likely.

SGP Strategy:

1. Understand Correlation: Positive correlation (winner + star player stats) gets reduced odds
2. Look for Negative Correlation: Outcomes that work against each other (rare)
3. Player Props Add Variance: Individual performances are harder to predict
4. Line Movement Matters: SGP odds don't always update as quickly as straight bets

SGP Parlay Math:

The correlation adjustment means SGPs have even worse expected value than traditional parlays. The convenience of betting correlated outcomes comes at a mathematical cost.

For probability analysis on individual outcomes, see our Probability Calculator.

Understanding Expected Value (EV) in Parlays:

Expected Value tells you the average amount you'll win or lose per bet over time:

EV = (Probability of Winning x Payout) - (Probability of Losing x Stake)

Example: 3-Leg Parlay at -110 Each

• True Probability: 0.5238 x 0.5238 x 0.5238 = 14.37%
• Sportsbook Payout: 6.0x (+500)
• Fair Payout for 14.37%: 6.96x

EV Calculation:

• Win: 14.37% x $500 = $71.85
• Lose: 85.63% x $100 = $85.63
• EV: -$13.78 per $100 bet (-13.78% house edge)

EV Comparison by Bet Type:

Breaking Even on Parlays:

To break even on a parlay, your win rate must exceed the breakeven percentage:

You need to beat the true odds by ~10-15% just to break even on parlays.

For detailed EV analysis of your bets, try our Expected Value Calculator.

Mistake #1: Adding Legs for Bigger Payouts

The Problem: Each additional leg compounds the house edge

• 3-leg parlay: 12.5% house edge
• 6-leg parlay: 13.5% house edge
• 10-leg parlay: 14.2%+ house edge

Better Approach: Limit parlays to 2-4 legs maximum

Mistake #2: Including Heavy Favorites

The Problem: -300 favorites add minimal payout but significant risk

• A -300 leg only multiplies your odds by 1.33x
• But failure rate is still ~25%

Better Approach: If you like a heavy favorite, bet it straight

Mistake #3: Chasing Losses with Parlays

The Problem: After losses, bettors try to win it all back with one big parlay

• This leads to emotional, poorly researched bets
• Parlays are the worst vehicle for chasing due to low hit rates

Better Approach: Stick to your bankroll management regardless of results

Mistake #4: Ignoring Correlation in SGPs

The Problem: Combining positively correlated outcomes

• Running back TDs when team is favored by 14
• Over total when backing heavy favorites

Better Approach: Understand how correlation affects true probability

Mistake #5: Not Shopping for Best Parlay Odds

The Problem: Different sportsbooks offer different parlay payouts

• Book A might pay 6.0x on a 3-teamer
• Book B might pay 6.5x on the same parlay

Better Approach: Compare parlay odds across multiple sportsbooks

Mistake #6: Betting Parlays as Primary Strategy

The Problem: Using parlays as your main betting approach

• Professional bettors rarely use parlays
• Long-term profitability is nearly impossible

Better Approach: Use parlays sparingly for entertainment, straight bets for serious betting

Mistake #7: Not Tracking Parlay Results

The Problem: Selective memory about parlay wins and losses

• You remember the big wins, forget the many losses
• Can't assess true profitability without data

Better Approach: Log every parlay bet and calculate actual ROI