im actually curious how accurate the lines they show are, vs if you used their api. do you know? theres a lot of noise in them as far as i can tell- just wondering if its real or if they are jiggling the numbers around to make it look more appealing.
Site Vs API are identical. There may be some extra latency (order of milliseconds) on the site due to render time etc but they both use the same underlying data source.
Do you mean the Betfair lines? I think their market is pretty accurate. More so than many traditional bookmakers, although a lot of them use Betfair to make their own markets now, so there's very little chance of arbitrage between them.
I've written an R library for the Betfair API[1], which I use every day to retrieve prices.
sorry i meant accurate in terms of what they show on the site vs what you can actually get when you try to trade. someone else answered that they are indeed accurate- has that been your experience?
The Betfair prices depend on market depth. It's data available through the API, so you can have a pretty good idea of what price you will be able to strike for any given bet size.
My experience with traditional bookmakers has been severely limited or closed accounts very quickly. I haven't used a traditional bookmaker for a few years now, betting solely on the exchanges and 90% of the time with Betfair. I do still have a Corals account, which was somewhat un-restricted through leveraging a contact within the company, but I think my max bet is only £200. As I haven't used it for while, I don't like the chances of it staying that way if I started pumping winning bets through it.
There have been various investigations conducted on Betfair prices, and they are usually a few ticks above traditional bookmaker odds. However, the over round on highly liquid Betfair markets is only 1%-2%, whereas a traditional bookmaker is generally significantly higher, more like 110%-120%, depending on the event.
One way to extract the best results from traditional bookmarkers, as far as horse racing is concerned, is to bet with Best Odds Guaranteed. In this scenario, you'll receive a winning payout at the highest price the selection reached, rather than the price at which you struck your bet. This works best in overnight markets, that is placing bets the night before the race. However, this route is also one of the quickest to restriction and closure.
