Most MT Users will be aware that on Monday the 14th of April Betfair introduced Data Request Charges.
During the development of the Data Request Charges system, Chromaweb co-operated with the Betfair API Team in the calibration of the scheme, and our experience during that process suggests that, with normal use of our software, the impact of the scheme on MT users will be minimal or none at all.
The main Window of MT now has a Data Call Monitor so that you can see how many Data Requests per second you are currently making.
The 'Data Calls per Second' is for all of the Trackers that you currently have running, and the 'Over 20 calls count' keeps track of the Total number of calls over 20 per second that you have made in your current MT session.
If you have instances where more than 20 calls have been made in any one second, then the 'Over 20 calls count' turns red and starts a running count of the total number of Data Request calls over 20 per second that you have made in your current session:
With MT, the most likely cause of calls exceeding 20 per second is over use of the Current Bets Alarm display, this is because the Data Call it makes to the API (getMUBets) is charged at 5 calls when no Market is specified, as is currently the case with the Current Bets display, so one way to minimize the risk of incurring Data Request charges is to set the refresh rate of the Current Bets Alarm to a high value, e.g. 10 seconds.
To get this screenshot we had to have the Current Bets Display refreshing at once per second and have 6 Trackers open simultaneously, so it's unlikely that you will incur significant Data Request charges using MT alone.
However, MT doesn't know what other applications you may be running and accessing Betfair with, so it can't monitor their Data Calls,and Data Charges apply to all of your use of Betfair at any given time, so if you are running other API applications, or the Betfair Website with a high refresh rate, you could still be over the limit, even though MT is under, so you should probably be aiming for maximum of 18 calls per second from MT.
To minimize the possibility of Users incurring Data Request charges,
you can now set, via the User Defaults Panel, a Default Call Saving Rate:
If you leave the Data Call Saving rate at its Default of 0 (zero), your Trackers will behave and Refresh as normal, but if you set a higher value, e.g. 2, then all Trackers except the 'Active' one will Refresh with a 2 second delay, whilst the 'Active' Tracker will refresh as normal, at your selected Refresh Delay ... in this case 0 (zero).
As stated previously use of our software on its own is unlikely to incur
Data Request Charges, and also Betfair will be allowing a period of grace
after 14 April when charges will be monitored but refunded, so we recommend
that you leave your Default Data Call Saving rate set to 0 unless you
are sure that you would otherwise incur unwanted Data Request Charges.
You can still choose to set different Refresh Rates for different Trackers at any time while the Trackers are running.
Single Trackers v Event Trackers
Some users have expressed a concern that Event Trackers, because they
show more than one Runner, might make a high number of Data Calls.
The answer is, they don't.
All calls to update market prices retrieve the prices for all Runners in an event, so whether a Tracker shows one runner or twenty, that's still just one call ... so, in fact, if you wish to track several runners in an event , you can reduce your number of Data calls by tracking them all in an Event Tracker rather than in several Single Trackers.
A brief summary of the Data Request Charges, from Betfair:
" On Monday the 14th of April we will be introducing a charge aimed at encouraging customers to limit high levels of API and Web requests for data made simultaneously in the same second. Customers will be allowed 20 free data requests in each second even if they are not betting. Requests above 20 in a second will be charged at 0.1p per request but any charge will be offset by commission and implied commission (equivalent calculation to commission but in relation to net losses). We will also be multiplying the commission and implied commission total by 5 to increase the offset. It is therefore possible for a customer to make more than 20 data requests in a second without incurring a charge as long as he/she is betting.
Full details of the charge may be found on the Betfair Charges webpage which is in the About Us section of the Betfair website. This includes a calculator helping you calculate additional free data requests above 20 per second that you can make without incurring a charge as a result of generating commission or implied commission. "