Soccer Half Time / Full Time odds relationship with HT and FT result?

[gereqi]

Hi folks, I have been searching a lot over Google and into this forum, but haven't got a clear explanation and maybe a formula of HT/FT odds if they have any relationship at HT and FT. I have been reading through www.betgps.com and http://forum.punterslounge.com/threads/108005-Half-time-Full-time-odds?highlight=half+time+full+time etc etc. but was able just to get a partial idea... Maybe you can explain me a little bit better why for example, in the tomorrow's match the odds are like this at HT/FT: Arsenal FC - West Ham United FT Home (1): 1.4 (probability 0.71) Draw (X): 4.6 (probability 0.22) Away (2): 6.75 (probability 0.15) HT Home (1): 1.85 (probability 0.54) Draw (X): 2.45 (probability 0.41) Away (2): 6.25 (probability 0.16) HT/FT: 1/1 : 2.05 X/1 : 4.05 2/1 : 22.00 1/X : 17.50 X/X : 7.75 2/X : 19.50 1/2 : 50.00 X/2 : 15.00 2/2 : 13.00 I have been trying to reproduce the formula given:

Quoting user JENSPM ... The chance of a win is, 1-(A+(B*C)) Where: A = the chance of Marseille winning or grabbing a draw at HT B = the chance of Chelsea winning at HT C = the chance of Chelsea losing the match IF they are winning at HT the correct odds would then be 1/(1-(A+(B*C))) ...

but I should be getting them wrong because I can not reproduce not even closer any of the odd types of HT/FT like 1/1 or X/1 etc. Maybe someone can help me and give me a hint or a lead?

[Paparazzo]

Re: Soccer Half Time / Full Time odds relationship with HT and FT result? I guess that in the formula you should add a higher juice to the HT/FT market. Going back to your example your odds are at a 108% on 1x2, so firstly you have to normalize the percentages are (note this calculation might not 100% correct!, ie. longshot bias), Then you should know what is the probability that given the result of the FT given the HT results (ie. if HT is 1 80% of the times there will be a 1 at FT). Then you can use the Bayes theorem to derive the probabilities of HT/FT to calculate the true odds and see how much is the margin. But at the end you'll see what I stated (higher juice is involved). In your example the juice of HT/FT grows up to a 118%! This is because it is considered as an "exotic" market or simply is considered as an acca. I hope it helps...