Betting odds Query 5:05 Warwick

punchestown

Folks,

Trying to get my head round this but cant for life of me. Hoping the maths experts can help please?

Above race, 3 runners 8/11 Fav, 11/8 and 12/1 shot. Right before the off, the 8/11 fav was withdrawn thus resulting in a rule 4 to the market. the rule 4 deduction is 55p in the pound. I cant seem to work it out to a t but bascially to my thinking, the 11/8 shot becomes something like a 1/2 shot (€1 at 11/8 less 55c for each euro) but the 12/1 shot pays 9/2 (€1 at 12/1 less 55c for each euro 12*.45+€1 bet) If this is correct then you could gurrantee a profit by backing both horses and a tidy one at that?? Where am I making the mistake?

Thanks

Healio

Well the big mistake there is that you dont actually know the horse is withdrawn. Once the horse is withdrawn you can look back and say oh yeah guarantee a profit, but you don't know the horse is (or will be) withdrawn. You could still theoretically back both for a profit, but that would be on the premise that the favourite runs and gets beat.

punchestown

it was clear 60 seconds before the off that the fav was being withdrawn. the horse was being led away from the start back towards the stabling area. The market was never reformed as is usually the case in these situations (w/d horse moments before the off)
aside form the point of knowing whether horse was being withdrawn or not, are the sums in my original post correct?

thanks

Crumbs

(0.45)*11/8 = 0.61875, which is around 8/13.

(0.45)*12/1 = 5.40, which is around 11/2.

Together they make a 77.4% book.

Beautiful!

punchestown

Thanks for the maths crumbs but how could the bookmakers make such an error with their rule 4 prices? I would have had the 2nd fav in at about 1/5 in a reformed market not 8/13!

Crumbs

It's just a flaw in the "rule 4". Any withdrawn horse priced between 4/5 and 4/6 results in a 55% deduction in the other prices, regardless of any other factors. Sometimes it works in the bookie's favour, sometimes in the punter's favour. I'm surprised that there isn't a computerised formula to work out a fair reformed market, similar to the one used for forecasts and tricasts.

Well spotted, if you picked up on it yourself yesterday.

punchestown

Crumbs wrote: »

It's just a flaw in the "rule 4". Any withdrawn horse priced between 4/5 and 4/6 results in a 55% deduction in the other prices, regardless of any other factors. Sometimes it works in the bookie's favour, sometimes in the punter's favour. I'm surprised that there isn't a computerised formula to work out a fair reformed market, similar to the one used for forecasts and tricasts.

Well spotted, if you picked up on it yourself yesterday.

Im afraid i cant claim credit for spotting this before the off. it was only the fact that I was opposing the fav (Risk Assessor) by backing the other 2 horses in the race that when working out the return, I noticed the abnormality. In view of Risk Assessors connections, I wonder did they notice the fact??

Crumbs

I wouldn't put anything past those gangsters!

Collie D

This was actually the only race of the day I watched and never even noticed (in fairness I didn't even notice the withdrawal until they'd jumped a vcouple) ...hope somebody did and cleaned up