Oscar needs a holiday

A large loss occurred today as a result of a bet placed in error. Although I’ve seen this before, the size of the loss made me investigate the problem.

Nearing the off time my bot stops trading and then there’s a break of 10 seconds to allow any bets placed to be matched. Then a greening algorithm runs 3 times, first to green at the available odds, then at 1 tick worse than available odds, finally at 2 ticks worse than available odds. The idea is to reduce any risk of leaving a bad position open.

On today’s event the first attempt placed a lay in error. This left 2 attempts to hedge out. Unfortunately both failed. Looking over my code, the greening part is probably the oldest. A quick look on the Gruss forum and the example code has been updated a few times, without me keeping up. The code I use is greening on old data. The most recent code greens on current data.

As the possibility of a similar error exists, I’m not prepared to carry on trading until I’ve fixed this code. Due to the amount of change required and testing I need to do, I’ve stopped Oscar and his American brother for now. Hopefully the coming Bank Holiday weekend will provide some opportunity to make the fix.

Hols bot



7 thoughts on “Oscar needs a holiday”

  1. If i read this correctly you had a loss because the hedge/close out didn’t fire? Do you utilize the SP option? Surely placing a ‘take SP’ bet would at least allow a close out position at the off as an ultimate back up. May not be the optimal but at least it would negate the worst. Just a thought.

    Liked by 1 person

    1. Hi Mike. You’re right, this is an obvious step that I’ve completely missed. The hedge may not be even but the liability would be reduced. I’ll code this in for now to get the bot trading again as soon as possible. The greening will still need to be improved but this is a first step.
      A really useful tip, thanks


  2. I use “Take SP” too but sometimes you are not getting good odds.

    I have also used a reverse bet (i.e. equal to how much has been traded in the opposite direction – outward leg) and using odds of 1000 or 1.01 to guarantee that Betfair matches. This is essentially the equivalent of asking a stockbroker to trade “at best”.

    Of course you don’t get odds of 1000 or 1.01. If you say lay at 1000 then you will get the best odds available when you place the trade. The same if you ask to back at 1.01. So long as it is done prior to the in-play then you will get the best odds available.

    BPT – http://www.betfairprotrader.co.uk

    Liked by 1 person

    1. Looking to guarantee getting matched by laying at 1000 or backing 1.01, is good enough 99.99% of time. However, black swan events do occur… Remember Ransom Note (https://www.theguardian.com/sport/blog/2010/jun/17/ascot-2010-day-three-live), I was luckily enough to back £2 of the £15 matched on betfair pre-race at odds of 1000.

      This is not the only time this has happened as well. Better off going 10 or so tickets either side of the price.


      1. Hi notfazed1. You are right, you can never guarantee anything. I’ve actually set my code at 25 because the stake would be at the preferred odds, I wouldn’t have the funds to cover the requested odds of 1000, meaning the bet wouldn’t be accepted. My bot doesn’t enter trading above 7 so a drift to 25, although not impossible, should be very rare. This is also why, when I do recode the greening, I’ll use Take-SP instead.


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