This topic relates to something Euler posted on the "Scalping - Momentum, Reinforcement and Speed" thread, and since the question I have doesn't really have to do with that discussion in general, I thought I'd start a new thread.
Euler: "The playing field is level as you can only poll price 5 times a second at Betfair. Any faster than this and you return stale data. Its the most level playing field there is from a trading perspective."
Is there a difference between polling prices and data requests? Obviously, data requests on the betangel software are recommended to 15 per second, just wondering if a bots' settings should be different? I would imagine they would have to be as to get some form of accuracy in anticipating time data?
Data requests/polling prices
There is a subtle difference between polling prices and data requests although polling prices is part of the overall data request count.
Betfair use what they call a 'Delta Cache' to cache pricing data. This is what is pushed out to API servers and thus applications such as Bet Angel.
The exchange updates this cache on an approx 200ms cycle.
Therefore if you request another price update faster than 200ms you will get the same response until the exchange completes a 200ms cycle.
This is why the auto-refresh in Bet Angel has a max of 200ms. It is pointless going any faster.
The data calls made by Bet Angel include more than just price information however. Data such as matched bets, unmatched bets, P&L, silks, event name, jockey name, market depth, account balance, traded volume and so on are also retrieved.
You can read more about this here - http://bdp.betfair.com/index.php?option ... Itemid=108
Betfair introduced their data charge threshold partly in response to this 200ms cap as some developers were trying to pull off pricing data unnecessarily quickly thus using valuable data bandwidth at the exchange.
You can read more about this here - http://bdp.betfair.com/index.php?option ... Itemid=108
Betfair use what they call a 'Delta Cache' to cache pricing data. This is what is pushed out to API servers and thus applications such as Bet Angel.
The exchange updates this cache on an approx 200ms cycle.
Therefore if you request another price update faster than 200ms you will get the same response until the exchange completes a 200ms cycle.
This is why the auto-refresh in Bet Angel has a max of 200ms. It is pointless going any faster.
The data calls made by Bet Angel include more than just price information however. Data such as matched bets, unmatched bets, P&L, silks, event name, jockey name, market depth, account balance, traded volume and so on are also retrieved.
You can read more about this here - http://bdp.betfair.com/index.php?option ... Itemid=108
Betfair introduced their data charge threshold partly in response to this 200ms cap as some developers were trying to pull off pricing data unnecessarily quickly thus using valuable data bandwidth at the exchange.
You can read more about this here - http://bdp.betfair.com/index.php?option ... Itemid=108