The Lab Library
Learn
Plain-English guides to reading a bet the way the Lab does. The math the books don’t itemize: correlation, the SGP tax, fair prices, trap legs. Taught for people betting their first season, no stats degree required.
Parlays & Correlation
Why Did My Parlay Lose on One Leg? The Math Nobody Shows You
Going 4-1 pays the same as going 0-5: nothing. Why the near-miss is the most common outcome of a good ticket, and how the house edge stacks with every leg you add.
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Betting Basics
What Is a Parlay? How Multi-Leg Bets Actually Work
One ticket, multiple legs: the odds multiply and every leg must win. How the payout is built, what a push does, and the three kinds of parlay you’ll actually meet.
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Betting Basics
How to Read American Odds: What +150 and −110 Actually Mean
Minus is what you risk, plus is what you win. The two formulas that turn any price into a probability — and why both sides of a coin flip cost −110.
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Parlays & Correlation
How Much Does a Parlay Actually Pay? The Payout Math, Leg by Leg
A 2-leg at −110 pays +264; fair would be +300. The full ladder through 5 legs, how to compute any slip in three steps, and where the missing money goes.
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Variance & Discipline
Is a Losing Streak Normal in Sports Betting?
A 55% bettor has a 91% chance of losing four in a row inside 100 bets. Why your record is not evidence yet, how many bets it would take to be, and the three things worth watching instead.
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Odds & Prices
What Is Line Shopping? Why the Same Bet Pays Different Odds at Different Sportsbooks
The same wager pays +200 at one book and +250 at another. Why odds differ, what shopping is worth over a season, and how to tell a real gap from a stale line.
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Parlays & Correlation
How to Check If a Parlay Is Actually Good Before You Bet It
The 4-step pre-bet checklist: standalone leg value, correlation, payout math, and trap legs. Run it on any slip before the money leaves your account.
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Parlays & Correlation
What Is the SGP Tax? The Correlation Tax on Same-Game Parlays, Explained
The gap between what your parlay would pay if the legs were independent and what the book quotes, with the napkin math worked out step by step.
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Parlays & Correlation
Same-Game Parlay Correlation: Why Your SGP Quietly Loses (and How to Spot It)
Positive vs. negative correlation, the 15–25% hidden hold on SGPs, and how to spot legs that move together before you lock them.
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ET Parlays is sports-analytics research and decision-support, not a sportsbook, and never a promise of a winning bet. New guides land as they’re written.