S.P. Calculation.
 

Out of interest, today at Mackay R6 had a field of 9 starters, and I layed every horse for the minimum $30 with S.P.

I expected to lose 5% commission whatever won because I thought an apportionate amount would be bet according to each's price for a set liability of $30, but when the S.P. prices were loaded only the fave showed a loss if it won the race. Fortunately it didn't.

Anyone knows how the amounts are calculated, and why only the fave (I presume) will show a loss?

My undertanding is betfair sp is calculated by settling all sp bets + exchange bets (which are set to go live or sp).

Its not like the tote where they just take 15%. (in this case 5%). So the sp can fluctuate quite a bit.

The issue is the liquidity in the market. While there may be 10K in the exchange betting up till the market is suspended, only a small percentage of this may change to sp. So where a horse had $100 at $4 $300 at $4.20 and $500 at $4.40. When the market gets suspended the $500 + $300 amounts might decided to lapse rather then converting to sp. So there is now $100 at $4 that is available. They add his $100 at $4 to the betfair SP then they try to match up the available SP bets.

Its highly open to manipulation by large money (intentional or not) due to the low amount of dollars going through it.

Does that make sense ? Betfair has a full page on it but I recon you already have had a read. It does give and example I think.

Any questions just ask.

Thanks, Wesmip.

As you say, it can be manipulated by its lack of liquidity, but I think that could back-fire.

I have missed a few Bet races races where I would have won. I thought I had done something wrong by not properly locking the bets in, but its possible they could not have been matched.

I might have a few more bets laying the field and see if I can come up with anything worthwhile.

Thanks.
Michael.

Kudos and thanks to Michaelg for raising this one.

Laying the whole field and only having the fav a loser (or even better no losers) is my life. I have never looked at Betfair SP, until now. I always thought it was for fools.
I thoroughly checked past UK & IRE results and was pleasantly surprised with what I found. Rarely is BF SP less than 100%, and I struck one recently that was 112%.
Tonight will be night 25 of using BF SP and if it's a loser it will only be the 2nd losing night.
Because the UK markets are pretty well formed before 10.00pm (QLD time) you can be reasonably confident of laying and having a minimum number of losers (if any) per race, without staying up all night. With an almost 100% guarantee of laying every race at at least 100%, if you have an idea of what you're doing this is virtually unbeatable.
Cheers Michaelg.

Hi Mark.

I'm glad I'm somewhat instrumental in your success with S.P laying. It sounds a very powerful method you've devised.

Do you have the web address where one can obtain the S.P. prices for past races in the U.K?. And here also just in case this, or any other anomaly applies to our races. I didn't know it was available.

If the S.P. market is rarely less than 100% it therefore wouldn't make sense to back horses with S.P. But maybe it's different here, I've obtained some amazing prices when compared to TAB divvies.

The SP's are available on Betfair.
Near the top of the page, go along to English - Aus & NZ, and change it to English - UK.
Then choose Horse Racing from the black tab.
Then just below that click on Form/Results.
That opens another window, from there select Cards & Results.
Then your away with the calendar or yesterday's results.
Click any meeting, any race etc and you get the full results, including BF SP's and the %.

I've found our SP's to be a bit hit & miss, with a lot being less than 100%.
Once I've built this bank up I'll be doing USA SP's as well. They are all over the place ranging from 70% to 130% just in the last couple of weeks. It must be down to the amount of $ available.

How do you lay the field on SP when you don't know what the SP will be and hence how much you need to wager on each runner? Do you lay flat stakes on all runners as this would make the market % irrelevant?

As Mark says, you have first have to ensure the market settles so that you've got a good idea what the S.P. prices will be.

When he is satisfied, I believe he then lays every horse on S.P. for the same amount. S.P automatically "dutch-lays" them all, and if the market is more than 100% its then difficult to lose.

He might identify suitable situations/factors to lay them. I haven't looked at it yet so I'm not certain what he does.

Hi MichaelG, So what your saying is that on Betfair, you can somehow automatically dutch lay every horse in a race, so in theory whatever horse wins your payout figure is less than what you have recouped from all the other horses....?

Is there some sort of minimum outlay to do this.

I did follow those links in that UK Betfair site to the results page, but didnt really follow the figures that well. Wasnt really sure what all the %'s meant etc.

Regards, Paul

Yes, every horse can be layed for the same amount, the minimum being $30.

However, as Wesmip1 says in post 2 of this thread it can be open for manipulation (or an unusual market percentage) because of the lack of money in it.

I stated in post 1 of this thread that out of interest I layed every horse in Mackay R6 expecting to lose about 5% whatever won/lost the race, but I was surprised that I would have won on every horse except the fave. That is what prompted me to start this thread. In fact I again layed the field in another race, but every horse turned out to be a loser so I ended that.

However, it appears due to the higher amount of money wagered in England that there may not be this anomaly. I would assume this to be true because of Mark's success there.