Parlay

A parlay (called an "accumulator" in the UK) is a single bet that combines multiple selections. All legs must win for the parlay to pay out. If any leg loses, the entire bet loses.

How Parlays Work

Each leg's odds multiply together:

Parlay odds: 1.91 × 1.91 × 1.67 = 6.09

A $100 bet pays $609 if all three hit. Miss one leg? You lose $100.

Why Parlays Are -EV

The vig compounds with each leg:

At 5 legs, you're giving up 22.5% to the house before the games even start. This is why sportsbooks love parlay bettors—they're the most profitable customer segment.

The Math Problem

Even if each leg is a coin flip (50%), a 4-leg parlay wins only 6.25% of the time. At standard parlay odds, you need to win far more often than probability allows.

Expected value of a -110 4-leg parlay:

• Win probability: 50%^4 = 6.25%
• Standard payout: ~12:1
• Fair payout should be: 15:1 (1/0.0625 - 1)
• EV: -18.5%

You're losing 18.5 cents per dollar bet, on average.

When Sharps Use Parlays

Sharps almost never bet parlays. The exceptions:

Correlated parlays. If legs are positively correlated (not properly priced by the book), parlays can have +EV. Example: Team A to win AND the over, when Team A's wins are typically high-scoring.

Line combination arbitrage. Occasionally parlay odds misprice relative to individual lines, creating edge.

These situations are rare and books actively prevent them.

Same-Game Parlays (SGPs)

Books now heavily promote "same-game parlays"—multiple props from a single game. The vig on SGPs is even worse than standard parlays because:

1. Legs are often correlated (book adjusts against you)
2. Odds are set by algorithm, not market
3. The "fun" factor justifies worse prices

SGPs are entertainment, not investment.

Related Terms

• Vig — The house edge that compounds in parlays
• Square — Recreational bettors who love parlays
• Edge — What you need (a lot of) to overcome parlay vig