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Retrospective - API Release To Prevent Minimum Bet Abuse - 19th June

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  • WTPooh
    replied
    You can lay any size from 0.01 to 1.99. Just use a price from my first post.
    But there are several limitations for resulting price: 1. Liability must be >= 0.008 (you can't lay 0.2@1.03) 2. Some sizes will not be acceepted (like 1.49@1.01).

    Leave a comment:


  • WellDoneSoft
    replied
    Originally posted by WTPooh View Post

    For me everithing works fine.
    Except when you need to lay at 1.03 or less than £0.2, then it becomes tricky, doesn't it.

    Leave a comment:


  • WTPooh
    replied
    To lay 0.2@2:
    1. Lay 2@1.04
    2. Cancel 1.80
    3. Replace price with 2

    For me everithing works fine.

    Leave a comment:


  • WellDoneSoft
    replied
    Hello!

    I have repeatedly attempted to lay 0.2 at prices up to 100.0, and failed.

    So this:
    size price
    0.01 1.8
    0.02 1.4
    0.03 1.27
    0.04 1.2
    0.05 1.16
    0.06 1.14
    0.07 1.12
    0.08 1.1
    0.09 1.09
    0.1 1.08
    does not appear to be valid at the moment: it could have been so yesterday.

    I initially thought the new change meant to prevent users laying to liabilities less than 0.01, but the above does not tally with this assumption, as the liability of £0.1 @ 100 is £9.9 and yet no bet is placed.
    Last edited by WellDoneSoft; 20-06-2020, 02:11 PM.

    Leave a comment:


  • bfexplorer
    replied
    Originally posted by Cymatic View Post
    URGENT

    I understand that there must be an urgent need for the change, but this was unplanned and is causing havoc for API software users.

    So I must ask you to consider reversing this change immediately and instead just block the accounts of anyone found to be abusing bet rounding. That would at least give us the chance to work together to come up with something in an orderly manner that doesn't cause havoc for innocent software users and software suppliers!

    Thank you.
    Cymatic, I agree with you only with one point, there is no documentation for this error message and basically betfair documentation is big mess, a lot of changes are not documented. Missing enum entries and so on..

    On the other hand, it is betfair T&C and they can do whatever is better for betfair business model.

    I hope you will not start quarrel like geoffw123 started on another thread when I stated my opinion.

    Yes, betfair tolerated placing bet under minimal bet size and we all betfair software vendors implemented that algorithm, but it seems not all vendors do what they are doing right?

    Because when during this "small bet placement" operation if anything goes wrong you need to cancel original minimal + small bet stake, and not leaving it on market as your software and bet angel does. Because then of course user could take actually bigger loss than with it original bet opening trading session.

    Watch my video, showing my app:

    https://youtu.be/Xf5ysUiBzPU

    When bet placement failed original bet was cancelled.

    My app offers more automation than your one, and when user places bets manually then he/she notice error messages when placing small bets, so it is his responsibility to act correctly.

    When small bets are placed in automation, I have got a lot of such bots called Close Bet Position, then even such bots when places small bet detects error and stops its activity.

    Well basically users place bigger bets when trading either manually or fully automatically, so problems could occur only when my closing bots try to level profit loss evenly to all selections, so small bets are being placed, and in my video you can see that betfair still accepts small bets, well you mentioned that as well, 0.8 stake amount, but on my video you can see that on back side I was able to place even 0.5 Eur stake.

    I set limits to my bots to 0.4 * MinimumBetSize defined by betfair per different currencies.

    Leave a comment:


  • WTPooh
    replied
    You can use different odds for different sizes. Here is my results for different sizes:

    size price
    0.01 1.8
    0.02 1.4
    0.03 1.27
    0.04 1.2
    0.05 1.16
    0.06 1.14
    0.07 1.12
    0.08 1.1
    0.09 1.09
    0.1 1.08
    0.11 1.08
    0.12 1.07
    0.13 1.07
    0.14 1.06
    0.15 1.06
    0.16 to 0.19 1.05
    0.2 to 0.26 1.04
    0.27 to 0.39 1.03
    0.4 to 0.62 1.02
    0.63 to 0.79 1.03
    0.8 to 1.24 1.01
    1.25 to 1.59 1.02
    1.6 to 1.99 1.01

    But there are some other problems. For example you can't have a lay bet 1.49@1.01.

    Leave a comment:


  • geoffw123
    replied
    This is unbelievable.,
    Agreed, they also compounded the problem by not explaining in detail what the change was, they left us to try and figure it out. In addition they dont seem to have have made a 2nd statement on the issue, despite all the App. forums blowing up with complaints yesterday from Developers and users alike.

    I would phrase it a little differently than when you said "You have allowed this for 20 odd years,", as I would say, being able to green up with sub 2 pounds is a vital and important feature all Apps need to be able to do.

    It does make you wonder why BF just didnt simply suspend the account of the abuser, rather than cause chaos with a rushed ill thought out modification ?


    Leave a comment:


  • LiamP
    replied
    Originally posted by BetfairDeveloperProgram View Post
    We made an emergency release earlier today to prevent consistent attempts to take advantage of bet rounding.

    Any bets that are placed to benefit from rounding will now be rejected with the error INVALID_PROFIT_RATIO

    Apologies for the lack of notice regarding this urgent release.

    Betfair Developer Program
    This is unbelievable.

    Surely you did a quick MI on the impact this would have before releasing to production without warning users, I can't honestly believe it.

    You have allowed this for 20 odd years, I am sure it could wait 1 more week.

    Leave a comment:


  • Gamblr
    replied
    That's pretty bad really, not only it breaks existing software but it's also creating major delays on apps being developed at the moment (like mine..). The fact that we had to do a workaround to cashout with lower stakes was already pretty bad. If Betfair made its cashout service "public" we wouldn't need to do workarounds and Betfair would have much more control/insight over the abusive strategies.

    Perhaps the abusers are premium charge payers so there's no interest in blocking such accounts

    Leave a comment:


  • escalater
    replied
    Apologies for the lack of notice regarding this urgent release.

    Thats not much use for all the havoc you have caused !!!!!!!

    Leave a comment:


  • jonnyf
    replied
    FYI, for anyone trying to make their software work over the weekend while we're waiting for Betfair to sort this out, there is a workaround possible for greening up anything with odds above 2 or so:

    1. If a lay bet is required, send a £2 bet at odds of 1.8
    2. Cancel up to £1.99 of it (this operation is accepted at odds of 1.8, just not at odds of 1.01)
    3. Use replaceOrders to move the odds from 1.8 to whatever is desired

    Obviously this doesn't work for any runner with current odds of <=1.8 as the initial £2 bet will just get taken straight away. Anything with current odds of < ~2 is at risk of this happening if the market moves, but for my own programs this fixes a large percentage of API calls that failed yesterday.

    Leave a comment:


  • Cymatic
    replied
    URGENT

    This change that was intended to prevent abuse of bet rounding, has unfortunately broken various well known API software programs used by large numbers of customers, because it is preventing the software from greening up by using a lay bet with a stake of less the £0.80 (or currency equivalent).

    Software needs to be able to green-up (cash-out) by using the well established long-standing procedure:
    1. If the greening requires a lay bet, then send it at odds of 1.01 for the permitted minimum stake.
    2. Cancel part of the bet so that it has a smaller stake.
    3. Move the small stake to the required price to green-up (cash out).


    I understand that there must be an urgent need for the change, but this was unplanned and is causing havoc for API software users.

    So I must ask you to consider reversing this change immediately and instead just block the accounts of anyone found to be abusing bet rounding. That would at least give us the chance to work together to come up with something in an orderly manner that doesn't cause havoc for innocent software users and software suppliers!

    Thank you.

    Leave a comment:


  • geoffw123
    replied
    Hi Jonny thanks for the feedback

    I didnt really catch the error properly when i saw it today on my App, so somewhat guessing here. Also it was ages ago i wrote the greenup code, so not fresh in my memory. From what I recall, the trick that everyone uses for low stake greenups is as follows

    For a lay bet of 50 pence at odds 3.2
    a: Place lay bet of 2.00 at oddds 1.01
    b: Cancel that bet but partially of £1.50
    c: Replace odds of remaining 50p fragment of bet from 1.01 to 3.2

    I think with the new API change caused the Cancel operation to fail (I was left with an unmatched lay of 2 quid at 1.01)
    Also the error message I got back from BF contained "sizeReduction":1.5, implying it was stage b: the Cancel operation that failed.

    Hopefully Betfair will detail the change tomorrow if they dont decide to roll it back.

    Leave a comment:


  • jonnyf
    replied
    I've messed around with a few API calls to try to figure out what gets rejected and what doesn't. Hopefully BF can clarify, but it looks to me like lay bets must have at least 0.8p (as in £0.008) liability to get through. So if you want to place a lay bet at 1.01 (like a green up strategy would before using replaceOrders) it has to be at least £0.80 (£0.79 gets rejected). But at odds of 1.80, you can place a £0.01 bet (at odds of 1.79, the same £0.01 bet gets rejected). I don't think back bets are affected but not 100% sure.

    Leave a comment:


  • geoffw123
    replied
    I havent studied exactly what is going on here after this modification, but I can confirm this has broken my App too, some small stake green up attempts are now failing. (Some still work, dont know what the distinction is)
    Also from reading the BetAngel forum today, lots of people are complaining that green up attemps are failing and causing them to lose money. One other person commented they were using another commercial App. today that is also now failing to green up sometimes.

    TLDR: Betfair you really cant make hurried changes like this that break lots of your approved Apps !! I think this one needs to be rolled back

    P.S
    BetAngel have been talking to Betfair Tech Support and have already released a patched BetAngel to workaround todays rushed API change.

    It would be nice if Tech support here could explain exactly what triggers this INVALID_PROFIT_RATIO error to the rest of us so we could also figure out a workaround. Thanks
    Last edited by geoffw123; 19-06-2020, 11:03 PM.

    Leave a comment:

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