Betfair directory listing of prices

[MLW]

Hi all - apologies if a post has already been done on this. I've been messing around with a strategy and it looks promising - I've been live testing it but want to look at previous data. I'm particularly interested in seeing where the fav got matched at the lowest lay price in play. I've been using the Betfair directory of prices and downloading them to inspect the prices. One thing I've noticed quite often is that short priced favorites have never lowered in price. For example, start price of a horse is 2.40 and IP price is the same, 2.40. I appreciate this can and does happen but the data shows this to have happened far too often which makes me think it's flawed. I think i read on another post that it's to do with the IP price only being recorded when it's at a certain volume. My question is, does that mean that the Betfair directory prices data is flawed and not the best to backtest against? If that's the case, what data source can I use that's more accurate? Many thanks in advance.

[jamesedwards]

Hi all - apologies if a post has already been done on this. I've been messing around with a strategy and it looks promising - I've been live testing it but want to look at previous data. I'm particularly interested in seeing where the fav got matched at the lowest lay price in play. I've been using the Betfair directory of prices and downloading them to inspect the prices. One thing I've noticed quite often is that short priced favorites have never lowered in price. For example, start price of a horse is 2.40 and IP price is the same, 2.40. I appreciate this can and does happen but the data shows this to have happened far too often which makes me think it's flawed. I think i read on another post that it's to do with the IP price only being recorded when it's at a certain volume. My question is, does that mean that the Betfair directory prices data is flawed and not the best to backtest against? If that's the case, what data source can I use that's more accurate? Many thanks in advance.

What country horse races are you looking at?

[MLW]

Thanks for your reply - UK and Ireland.

[jamesedwards]

Thanks for your reply - UK and Ireland.

Then there should normally be enough volume traded at most prices to make the lowest traded price meaningful, I would have thought? How often do you see the lowest traded price match SP?

[MLW]

I've not noted anything down but I would say roughly out of every 20 races, 6 or 7 of them the SP and IP price have been exactly the same. These are strong favs too of odds lower than 2.90 and the second being 5.o and above. Just doesn't seem right.

[jamesedwards]

I've not noted anything down but I would say roughly out of every 20 races, 6 or 7 of them the SP and IP price have been exactly the same. These are strong favs too of odds lower than 2.90 and the second being 5.o and above. Just doesn't seem right.

Yeah that doesn't sound right. Have you got any specific recent examples where the prices are the same. I will check against my records.

[MLW]

As an example - 5/6/19/ 15.20/ Wexford. Fav was SP 2.76 and IP min was 2.74. I should have mentioned too that these are long races, 2m4fs and above. Thanks.

[jamesedwards]

When I said recent, I was hoping for a little more recent than 6 years ago.

Got anything from this year?

[MLW]

haha sorry. Here is a recent one : Haydock / 19/03/25 / 17:35 / 3m hcap - SP 2.92 and IP min 3.

[jamesedwards]

haha sorry. Here is a recent one : Haydock / 19/03/25 / 17:35 / 3m hcap - SP 2.92 and IP min 3.

I have this down as lowest traded price of 2.4, although that does include pre-off so could have been before SP.

[MLW]

ok thanks for checking. I am thinking of using Racing Bet Data as that apparantley too is based on Betfair's exchange prices.