great video that - love the way the guy is trading the fav and then must be thinking "what the f*ck" and quickly moves over and takes some 29, pauses, then must be thinking what the f*ck again, then goes for it massively just as the race ends

Richard LL 29 Dec 11 00:55 
did we not have an integer overflow problem when the bat IDs reached a significant figure, I rememember all the IT guys laughing their c*cks off at error at the time.


that's exactly what happened.

Presumably on the real betfair screen there were prices available on the other runners due to cross matching. I'd assume that nearly all trading on this race was done on the winner (though I'm not a horse person and neither do I understand much of the API screen in the video) and that every time Betfair skims an ammount it goes missing rather than getting logged as bet.

It does seem plausible that 1424 could be that number.

When someone puts up a lay of 29, combined with other lays in the race, a back appears on the other runners to the inverse value - approximately thanks to betfair cross matching software.......... this would explain why the favourite gets shorter in price because the other runners hit 1000s before the favourite did and it tends towards the inverse of 29.

When anyone takes one of those backs, the money is distributed amongst the other runners. I don't know how this shows up on the market info and hopefully one of the regulars who looks into those things will know, but it seems plausible that it isn't assigned in the way we'd expect it to be - on top of that, there's often a little left over (that betfair keep) and who knows where that's assigned.

If you lay the 1.04 with Betfair's skimmer (referred to inaccurately by the firm as 'best price execution') then you'll actually bet the appropriate amounts on all the other horses to make sure you've got what looks like a lay of 1.04

After you've got the price you've been promised, if there are pennies left over, they go in Betfair's coffers.

In a normal race, there would be lots of genuine people trying to bet 1.04 say, but in this instance it would almost all be as a result of the huge sum sitting at 29 creating the 1.04 (seems a bit bigger when I look at the video, but that's because you have to bet the second fave at 7/1 and so on)

That's what happens in the football markets with the main market making lumps. About 1 second before all suspensions the lumps disappear, as if they're directly connected to the suspend operation. I commented on this  when it first started happening quite a few months ago, as it now appears that the main lumps are BF's, either directly or sub contracted.

The 29.0 lay money disappears in an identical manner.

Isn't it something to do with "keep bets" ie the 29 was put into the market in-play and not as a keep bet therefore gets cleared on suspension?

Oh I see now, so the price stalling at 29 is due to the system busy matching up a potential 21 million pay-out relative to someones exsposure? all seems a bit odd really and open too topical debate regarding the conditions and mechanisms at work within the betfair API.

of course, makes sense, but points the finger at mystery allowance of huge betting exsposure in-play?

We have identified the issue and replicated it in a test environment last night. A fix was applied overnight, and is now subject to rigorous testing. A further update on this will be made today.

So put in a fix, then let customers do the rigorous testing

BF claim now to be in full possession of all the facts .... if so they are keeping them under their hat.

just to state the obvious briefly, we're dealing with not one but 2 oddities here.

1 - the amount that appeared, and
2 - the price

that coupled with the fact that BF claim to have suspended the relevant account to me fairly clearly suggest that this was a deliberate exploit of a hole someone found. in which case, it also seems likely that

1 - the account involved had very little money in it
2 - the actual money was being made elsewhere.

I would therefore suggest that the accounts involved in the first trades made on purple at silly prices will be the ones to look at. anyone know how much got matched over there?

if the above is correct, whoever was involved would know it was a one-shot deal. so they'd need to make as much as possible from the one coup. which makes it a bit odd they didn't go for a higher profile race.

what's also odd is, if this is basically the same problem as already occured with bet IDs, why did no one think to test this scenario when that was being fixed?

apologies if this is old ground. not had time to follow all threads on this closely.

Would be surprised the customer hasnt been hung out to dry if there was anything at all malicious in it. Police etc. this hasnt happened.

At some point during the almost inevitable third party investigation I would like to understand a lot more about the "customer in question".  My opening question: has this "customer" ever worked for Betfair?

And Brendanuk1, I'm sure it's not necessary to remind everyone that if someone were of the view something malicious has happened here and they had reasons to suspect a crime had been committed, they would of course be duty bound to inform the police.

I read the money came on less than a minute into the race when the horse was at the back.ATR had the race on a split screen at the time.
It would be interesting to see the figures matched on the purple place for the race.Not sure if they have been posted anywhere ?

So the theory is that the BF lay was just to increase the price of the **** horse at the purple? The Sting is a great film, still watch it when it's repeated even after all this time :)

A couple of questions that have already been mentioned are:

What would have happened if the horse had lost?

Why not choose a race with greater liquidity/amount of punters to take the lay money on BF and lay it off at a silly price on purple for you to back?

Has anyone actually confirmed yet how much was matched at purple?

hmmm. latest update still doesn't explain how it happened (although it does state the full value of the lay was the int32 max in pence), in fact it's just a reiteration of what's been previously said.

perhaps they don't want people to know.

"devastated" is a bit of a strong word as well.

less than 1k in their account though, so a recreational bot?

can we assume that the missing 1424 was cross matched? wonder what proportion of that is then lost to the cross matcher?

how does a bot "develop" a fault, exactly?