Probabilities and fair odds
- Maths reviewed by Josh Miller
- Tested by Diana Westfield
A half time full time calculator splits each team’s expected goals between the two halves and prices all nine HT/FT results. With 1.6 xG for the home side and 1.1 for the away side, and 45% of goals in the first half, Home/Home lands 29.9% of the time and Draw/Draw 15.0%. The comeback, Away/Home, is 2.6%. Free, with fair odds for every combination and a box to check a bookmaker’s price.
How the half time full time calculator works
First-half goals for the home side are modelled as Poisson with an average of 1.6 × 0.45 = 0.72. Second-half goals at 1.6 × 0.55 = 0.88. Same for the away side. The CasinoCalcs calculator runs through every half-time score, every second-half score on top of it, and adds up which HT/FT box each one lands in.
The 45% matters. Change it to 40% and draws at half time get more common, which pushes up all three Draw/ results.
All nine results at 1.6 v 1.1
| HT/FT | Chance | Fair odds |
|---|---|---|
| Home/Home | 29.9% | 3.34 |
| Draw/Home | 16.4% | 6.09 |
| Draw/Draw | 15.0% | 6.66 |
| Away/Away | 14.7% | 6.79 |
| Draw/Away | 9.8% | 10.22 |
| Home/Draw | 4.9% | 20.24 |
| Away/Draw | 4.9% | 20.24 |
| Away/Home | 2.6% | 38.13 |
| Home/Away | 1.6% | 61.17 |
Level at half time happens 41% of the time here. That’s why Draw/Home is the second most likely result. It’s also the one people underrate.
The comeback prices
Home/Away and Away/Home are the big ones on the coupon, often 25/1 to 40/1. The model says Away/Home is fair at about 38, so a 33/1 (34.0) is short and a 40/1 is slightly over. Bookmakers know comebacks are the bet people dream about, and price them accordingly. Don’t take the long price on faith.
Where it can mislead
Teams change at half time. A side two up eases off, a side behind throws on a striker. The model’s halves are independent, so it can’t see that. In practice it’s a little generous to Home/Draw and Away/Draw and a little mean to the leading team holding on. Treat the numbers as a starting point.
For full-time exact scores see the correct score calculator, and for draws as insurance the draw no bet calculator.
Nine outcomes means most HT/FT bets lose. BeGambleAware.org is free and confidential if you need it.