This calculator compares the two prices in implied probability and gives you the exact cost of the move.
How to judge a line move
Convert both prices into implied probabilities: the difference is the probability the bookmaker charges you for the half-point.
You then have to compare that cost with the true probability that the result falls into the interval you gained. In football, moving from “over 2.5 goals” to “over 1.5 goals” captures matches with exactly 2 goals: roughly 20 to 24% of fixtures depending on the league. If the bookmaker charges you 30 probability points for that interval, the move destroys value.
The key lines to know
| Sport | Sensitive line | Approximate frequency |
|---|---|---|
| Football | Total at 2 goals | 20 – 24% of matches |
| Football | 1-goal margin | 28 – 32% of matches |
| Basketball | 3-point margin | Peak of the NBA distribution |
| Tennis | Games handicap at 3.5 | Around the single break |
Around these values a half-point is genuinely expensive and is priced accordingly. Away from them, the bookmaker often charges more than the true probability: that is where line moves are worst.
Frequently asked questions
How do you compare every line the bookmakers offer?
By hand it is impractical: each bookmaker offers several lines per market. The Stats&Bet odds comparison shows them side by side for every French operator, with the matching fair odds.
Do French bookmakers let you buy points?
Not in the explicit form used in the United States. In France you simply pick another line from the list on offer — the effect is the same, and the cost calculation is identical.
Does an Asian handicap change the calculation?
Quarter lines (−0.25, −0.75) add a partial refund possibility, which makes a direct comparison of implied probabilities imperfect. The calculation still gives a good order of magnitude, but think in three outcomes (win / refund / loss) to be exact.