How do I compare sportsbook prop odds for free?
Short answer: Find the same player, stat and line at two books, convert each book's over and under prices to no-vig probabilities, and compare them. OpenSlate's props page does this for free for every player line posted at both DraftKings and Pinnacle, refreshed through the day.
Step by step
- Match the line exactly. Same player, same stat, same number (5.5 rebounds is not 6.5).
- Write down both prices at each book, over and under.
- Convert to no-vig probabilities (how), so each book's margin does not distort the comparison.
- Compare the two probabilities. The difference in percentage points is the gap.
- Check the times. Prices change often (see how often); compare quotes read close together.
The free shortcut
OpenSlate's props page does steps 1 and 2 for every player line posted at both DraftKings and Pinnacle, by sport and by player, refreshed through the day. Each player page lists both books' over and under prices side by side. The full gap calculation, line history and alerts are part of Pro.
Live figures appear here while today's lines are posted.
Comparison is market data. It tells you where two books disagree, not who is right.
A worked comparison
Say both books post rebounds 6.5 for the same player. DraftKings has Over -105 / Under -125; Pinnacle has Over +110 / Under -140. DraftKings' no-vig under is 52.1%; Pinnacle's is 56.0%. The books disagree by about 4 points on the under. Before reading anything into that, check when each price was read and whether there is injury news on that team.
What to watch for
- Alternate lines. Books also post the same stat at other numbers with different prices; only compare the main line to the main line.
- Limits. A price you can only bet small is less meaningful than it looks.
- Promotions. Boosted odds are marketing; they are not the book's view of the probability.
Comparing more than two books
The same method works with any number of books: convert every book's prices on the identical line to no-vig probabilities and line them up. In practice one reference book is enough to start with, because what you want to know is whether the price you can bet is generous next to the market's best estimate, not which of eight retail books is furthest from the rest.
Keep a record
If you compare prices regularly, note the time, both books' prices and the line each time you look. A simple record turns impressions into evidence, and it lets you check later whether the gaps you noticed actually closed in your favour.
Related questions
- What does closing line value tell me?: what beating the closing price shows, and what it cannot.
- How often do prop lines move?: today's measured share of lines whose price changed at each book.
- What is the vig on DraftKings props?: how to measure the margin, with today's medians at both books.
- What is a market-maker sportsbook?: how market makers and retail books differ, and why it matters.
Every answer on these pages is market data and education. OpenSlate does not publish free picks and does not tell you what to bet; it shows prices and measurements.
More: Removing the vig: how to turn two prices into a fair probability · Why Pinnacle is the reference price · Closing line value, explained · Why parlays cost more than the same bets straight · Why player prop lines move · Is DraftKings or Pinnacle sharper on NBA player props? · How do I calculate a no-vig price? · What is a +EV player prop? · Why do DraftKings and Pinnacle prop lines differ? · What is a Trap Over? · Are NBA rebound unders profitable? · What does closing line value tell me? · How often do prop lines move before tip-off? · What is the vig on DraftKings player props? · How do injury reports move NBA prop lines? · What is a market-maker sportsbook? · Is it better to bet the over or the under on player props? · Can you make money betting player props? · Can you bet at Pinnacle from the US? · What free tools help with player prop betting? · Does betting DraftKings when it disagrees with Pinnacle work? · What does over/under mean on a player prop? · How do sportsbooks set player prop lines? · What is a sharp bettor? · How do I convert American odds to implied probability? · What is a steam move in sports betting? · What are alternate lines on player props?
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