How a free bet's value is calculated
A free bet does not return its stake: if it wins, you only get the net winnings, (odds − 1) × amount. Its average value is therefore true chance × (odds − 1) × amount. Babeth knows the true chance of every outcome (Pinnacle and Betfair Exchange, margin removed) and reads each bookmaker's odds on every scan: she computes this value for the outcomes of the next four days and keeps the best ones, updated every 5 minutes.
For a bet refunded as a free bet if it loses, the value is the bet's edge (true chance × odds − 1) plus, when it loses, the value of the refund free bet, estimated at its best use at the same bookmaker.
Example
A £10 free bet. On Arsenal at 1.50 (true chance 64%), it is worth 64% × 0.50 × £10 = £3.20. On Everton at 4.50 (true chance 21%), it is worth 21% × 3.50 × £10 = £7.35, more than double. The second only wins about one time in five, but over twenty free bets it returns twice as much on average.
Free bets often require minimum odds: set them in the field provided, Babeth only suggests odds above.
Frequently asked questions
What odds should I play a free bet at?
Long odds, usually between 3 and 8: since the stake is not returned, a free bet on short odds loses most of its value. The best choice is the price that maximises true chance × (odds − 1): that is what the converter computes. On very long outsiders the value often drops again, because bookmakers take more margin there.
How much is a £10 free bet worth?
Played as well as possible, between £6 and £8 on average depending on the bookmaker's margin; played at 1.50, about £3. The converter shows the exact value for the bookmaker and amount you choose.
Why are some options for subscribers only?
When the offered odds beat the fair odds, the option is also a value bet, the core of the subscription. The converter shows everyone the other options; subscribers (14-day trial included) also see these.