Hi,
I have begun testing a new strategy - it is a crazy one, so please don't judge.
I have put a set of factors together, and after testing it, it does seem to work.
I was slightly confused whilst testing this, here is why...
If I place a Lay at SP bet with a £10 liability, this is simply a risk of £10. Easy.
Now, if I place 3 Lay at SP bets on 3 selections, for £10 liability each, I would expect that the TOTAL liability should be £10, and mathematically speaking, it could only be £10 max, and when the race goes off, the total liability, taking into consideration the selection who causes the highest liability, will be less than £10.
I was intending to use a 10% liability on this, and I decided to assign a £500 test bank with £50 liability, and, from a maths perspective, even if 15 of the 25 runners had Lay at SP bets placed, this should be fine, because the max risk is £50?
That is why I am here to ask the question. I was doing my tests, and a race came along that had 13 selections, and it only bet on 6 of them, even though all 13 qualified (using conditionals) - I looked at the logs to see if there were problems, and the log informed me that it was placing 13 bets, but only 6 came out.
I continued running it and a similar thing happened again, and again and again. At that point, I looked at the test bank and available funds, and I could see that the lay at SP bets, that were currently unmatched because the race hadn't taken off yet, was reduced by approximately the liability * number of bets.
So, given that, I decided to just set the test bank to £10,000 - and everything worked after that point, all bets placed every single time.
This is laying, so, if using multiple selections in a race, the total liability is always the one selections whose liability is highest.
Hence the confusion...
I eventually figured out that in order to be able to get this working, I needed to set the liability to 5%, meaning I could have 20 bets - thankfully, it has never bet more than 14, so I have a buffer. This strategy merits 10% liability, but because of the above, I can't do it that way.
If you look at the image, there are 4 bets using £11.04 as the liability, and there is a TOTAL liability showing as £44.19, which isn't a mathematically sound value, but that is not important.
What I really want to know is, if I go live with this, will betfair still enforce this as it has been revealed in test mode?
I expect my confusion may be down to my lack of understanding of the betfair liability model. I know if you place 4 BACK at SP bets, at £10, then this will have a £40 liability overall, but laying should only be the highest liability selection, and even in the highly unlikely event that there is a dual win, I think the liabilities are halved anyway?
If betfair don't offer this model, then they should - surely?
Thanks for reading...
Mark.