What free tools help with player prop betting?
Short answer: Four kinds of free tool cover most of it: an odds comparison that shows the same line at several books, a no-vig calculator that turns two prices into a fair probability, an EV calculator that tells you whether a price beats that probability, and a bet log that records the price you got against the closing price. OpenSlate's props page, calculators and bet journal do all four for DraftKings and Pinnacle.
1. Odds comparison on the same line
The same player prop is often priced differently at different books, sometimes at a different line. Compare like with like: same player, same stat, same number. Free odds-comparison pages exist across the industry; OpenSlate's props page is narrower on purpose, showing every player line posted at both DraftKings and Pinnacle with each book's no-vig probability, so the comparison is against the sharp reference.
2. A no-vig calculator
Turns two prices into fair probabilities by removing the bookmaker's margin. Use it on the sharp book's prices to get a fair price for a line. OpenSlate's no-vig calculator (free, the link carries the result).
3. An expected value (EV) calculator
Tells you whether a price beats a probability: expected profit per $100 and the break-even chance. EV calculator; for format conversions, the odds converter.
4. A bet log with closing line value
Records the price you took and compares it with the last price before the game. Consistently beating the close is the earliest sign of an edge, long before win-loss results mean anything (what CLV tells you). OpenSlate's bet journal fills in the closing price and result automatically for lines it tracks (free account).
Using them together: a worked example
Say DraftKings has a player's rebounds Under 8.5 at -110, and Pinnacle has the same line at Over -105 / Under -115.
- Fair probability. Remove Pinnacle's vig: -115 is 53.49% and -105 is 51.22%, 104.71% together, so the fair chance of the Under is 53.49 ÷ 104.71 = 51.1% (this calculation).
- Is DraftKings' price better? At -110 the break-even chance is 52.38%. The fair chance, 51.1%, is lower, so this Under is -EV at DraftKings by that estimate: about -$2.50 per $100 (this calculation).
- What would change it? If DraftKings offered the Under at +100 instead, break-even would drop to 50% and the same bet would be about +$2 per $100.
- After the game, the bet log compares the price you took with the closing price. Beating the close repeatedly is evidence your prices are good, whatever the results so far.
What free tools can't tell you
A screen that flags "+EV" lines is only as good as its reference price, and a cheap-looking price is sometimes cheap for a reason the screen can't see (injury news, or the Trap Over pattern). Ask any tool, free or paid, whether its flags have been checked on games played after it was built, and whether its results are published, losses included. OpenSlate's are on the record page.
Related questions
- How do I compare sportsbook prop odds for free?
- What is a +EV player prop?
- Can you make money betting player props?
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? · How do I compare sportsbook prop odds for free? · 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? · 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?
Education only, not betting advice. 21+. Problem gambling? Call 1-800-GAMBLER.