Betfair wrote:Hi Peter,
Volume is always the total of customer stakes matched. Cross matching doesn't change that at all.
So if we match a £10 backer of Federer at 3.0 with a £20 backer of Djokovic at 1.5, then Federer volume goes up £10, Djokovic volume goes up £20, and total market volume goes up £30.
It's exactly the same if we match across markets - the volume is the total of customer stakes matched on that selection in that market.
Betfair cross matching explained!
If I back Djokovic for £30 at 1.50, but only £20 is available, the other £10 might come from laying a backer of Federer at 3.00
According to BF my £30 would show £40 matched on Djokovic and £20 Federer, as opposed to what I'd expect to see, which is £60 matched on Djokovic
This doesn't explain though why I can see my bet sat waiting on a selection, and the matched figure for that selection is indicating I should be getting matched, but am not
According to BF my £30 would show £40 matched on Djokovic and £20 Federer, as opposed to what I'd expect to see, which is £60 matched on Djokovic
This doesn't explain though why I can see my bet sat waiting on a selection, and the matched figure for that selection is indicating I should be getting matched, but am not
That was going to be my follow up to my first question aboveLeTiss 4pm wrote:If I back Djokovic for £30 at 1.50, but only £20 is available, the other £10 might come from laying a backer of Federer at 3.00
According to BF my £30 would show £40 matched on Djokovic and £20 Federer, as opposed to what I'd expect to see, which is £60 matched on Djokovic
This doesn't explain though why I can see my bet sat waiting on a selection, and the matched figure for that selection is indicating I should be getting matched, but am not
If i put my £1k in a que of £2k regardless of how that money was made up (direct on that selection or xm from other selections) According to BF replies all bets are still matched in there Bet ID order and only money matched on that selection is shown on its traded volume.
So at worst if every penny was matched on that selection £4k should show traded then mine is next, alternativly a less amount can be shown if a percentage of the XM money was matched else where or some of the money placed on this selction was shown elsewhere and XM there - but there should NEVER be a instance when the traded volume exceeds the amount (or twice the amount) which was showing on the selection when my oder was added.
It would be good if someone has a video showing a figure waiting then more than double that increased in the traded colum and their money still not touched and for betfair to comment on that.
Yes, exactly right Dallas - any discrepancies on a selection's matched volume through XM, should only show a lower amount required before you get matched, NOT a higher amount.
Unfortunately, this traded volume glitch happens often, and that's where the finger pointing occurs with regards to how BF are managing the matching of bets
Unfortunately, this traded volume glitch happens often, and that's where the finger pointing occurs with regards to how BF are managing the matching of bets
-
- Posts: 1744
- Joined: Tue Jan 19, 2010 6:28 am
I think it's easiest to see on 1.01 on horse races dallas. If you watch closely sometimes you will see say 2-4k waiting on the lay side and then all of a sudden 22k is matched. I imagine this will be explained as a refresh issue but it should be reasonably easy to see.
I'm a bit confused by how matched volume is computed for cross matching.LeTiss 4pm wrote:If I back Djokovic for £30 at 1.50, but only £20 is available, the other £10 might come from laying a backer of Federer at 3.00
According to BF my £30 would show £40 matched on Djokovic and £20 Federer, as opposed to what I'd expect to see, which is £60 matched on Djokovic
This doesn't explain though why I can see my bet sat waiting on a selection, and the matched figure for that selection is indicating I should be getting matched, but am not
Say I want to back Djokovic for £10 at 1.50.
Situation 1: There is a layer of Djokovic that matches this, then as I understand it the matched volume on Djokovic goes up by £20.
Situation 2: There are no layers of Djokovic, but instead I'm cross matched to lay a backer of Federer for £5 at 3.00.
How much does the volume on Federer go up in this case? I suppose if I was "originally" a layer here it would go up by £10 (twice backer's stake), but is it now the case that since I'm "originally" a backer of £10, it would go up by £20 (twice "original" backer's stake)?
2 selections are easy to understand and accept Peter. Where XM starts to become a grey area is when there's 3 + selections, as it becomes unclear as to who is getting matched and why. I don't like that, it makes the matching process look like it's being tampered with
Yeah, that's a great point actuallyPeterLe wrote:Yes I agree..
Also for anyone using automated strategies; you can see how things (EG WOM) is shown differently depending upon whether you have it switched on of off.. so could help or hinder a strategy..
I've come to realise over the years that WOM is quite often a trap, as much as a guide.
https://www.youtube.com/watch?v=3njy483sL-wPeterLe wrote:Cross matching was introduced on the 24th Nov 2010 (?) and I remember the build up wondering what would happen (there is a tread on here somewhere)
This explains what it is and is the best explanation Ive seen:-
https://api.developer.betfair.com/servi ... rtual+Bets
Although its a straight forward calcualtion; it seems to behave differently these days that when introduced originally.
Here is a video I did at the time (Pause the video as it plays and you can compare the subtle differencesin odds/money avail at those odds between one account with Cross Matching and one account with no cross matching)
https://www.youtube.com/watch?v=3njy483sL-w
Once you understand how it works; you will drive yourself mad trying to work out how to exploit it!
i saw this link
it's really hard to understand formula..and it's really really hard to undersand why in a moment(13seconds)the lay odds of third is different(4,1no xm-4,2 whit xm )
the book percentage is 101.5 for the lay column in that moment(and backers column is under 100percentage!), why the odds up?
ps:I think the key to understanding why the odds when they take you take you systematically disadvantage 'to look for in this cross-matching (english is not my language )
Folks,
Pre API-NG, Betfair had a doc that explained the cross matching principle, they had a example based on a football match and accompanying it they had a formula.
Does anyone have a copy of that formula please? (betfair still have examples of cross matching but they seem to have removed the formula)
I know betfair cross match against linked markets, I know that, but Im just looking for that original formula, if anyone can help
Thanks in advance
regards
Peter
Pre API-NG, Betfair had a doc that explained the cross matching principle, they had a example based on a football match and accompanying it they had a formula.
Does anyone have a copy of that formula please? (betfair still have examples of cross matching but they seem to have removed the formula)
I know betfair cross match against linked markets, I know that, but Im just looking for that original formula, if anyone can help
Thanks in advance
regards
Peter
-
- Posts: 3140
- Joined: Sun Jan 31, 2010 8:06 pm
1 / (N –∑ 1/(best to lay price of other runners))
Where N is the number of winners that market will have, e.g. for a “to win” market N = 1, for a place market with 3 winners N = 3.
For each runner calculate the available stake at that price as:
MIN(odds1*stake1, odds2*stake2...oddsn*staken) / [the price calculated in step a. above]
In plain English the stake you can match is limited by the payout (odds*stake) available on each of
the component bets that you’d need to match.
Where N is the number of winners that market will have, e.g. for a “to win” market N = 1, for a place market with 3 winners N = 3.
For each runner calculate the available stake at that price as:
MIN(odds1*stake1, odds2*stake2...oddsn*staken) / [the price calculated in step a. above]
In plain English the stake you can match is limited by the payout (odds*stake) available on each of
the component bets that you’d need to match.
Last edited by spreadbetting on Wed Jun 27, 2018 7:17 pm, edited 1 time in total.