Bettorly Blog

August 21, 2026

By JJ Roelant

Alternate lines are the same bet at a different number. Here's how the ladder works, and why home run props skip the usual line entirely.

August 20, 2026

By JJ Roelant

PRA is a basketball prop adding a player's points, rebounds and assists into one number. How the combo markets work and where they trip people up.

August 19, 2026

By JJ Roelant

You can take Over 14.5 points but there's no Under 14.5. That's because 14.5 isn't the line — it's a rung on the alternate ladder, and rungs go one way.

August 18, 2026 · Updated August 19, 2026

By JJ Roelant

Sportsbooks often list only the Over on a home run prop. On Kalshi and Polymarket the Under always exists — here's why, and what it actually costs.

July 22, 2026

By JJ Roelant

The Bettorly Discord is where we share daily highlights from the MLB & WNBA numbers — plus a place to request features, report bugs, and give feedback.

July 15, 2026 · Updated August 19, 2026

By JJ Roelant

How WNBA player props work: the main markets, why minutes move every line, and why a short season makes hit-rate windows matter more.

July 14, 2026

By JJ Roelant

How to bet on the World Cup, explained for US bettors: 3-way results, Draw No Bet, Asian handicaps, goals totals, and the 90-minute vs to-advance trap.

July 7, 2026

By JJ Roelant

What does last 15 games mean in betting stats? It's one of several hit-rate windows — L7, L15, L30, season — each a different slice of graded games.

June 23, 2026

By JJ Roelant

What is a hit rate in betting? It's the share of a player's graded games where a prop landed Over — here's what that number does and doesn't tell you.

June 2, 2026

By JJ Roelant

Why did my parlay lose when most legs hit? Here's how one miss sinks the whole ticket by design, and why that's not the same as bad luck.

May 12, 2026

By JJ Roelant

What does correlation mean in a parlay? A plain-English guide to positive and negative correlation, and why it changes a same-game parlay's odds.

March 31, 2026

By JJ Roelant

Does adding legs to a parlay lower your odds of winning? Yes — here's the multiplication behind it, and why longshot legs make it worse.

March 10, 2026

By JJ Roelant

How do parlay odds work? Each leg's decimal odds multiply together to set the payout — here's the math, in plain English, with a labeled example.

February 17, 2026

By JJ Roelant

What is vig in betting? It's the built-in margin sportsbooks bake into odds like -110/-110 so a true coin flip isn't priced as one.

January 27, 2026

By JJ Roelant

How to read American odds like +150 and -110 — what the plus and minus signs mean, how to convert odds to probability and payout.

January 6, 2026

By JJ Roelant

A parlay bundles several bets into one ticket for a bigger payout — but every leg must win. Here's how parlays work and how to think about them.