Self matching of prices on betfair

[davidcampbell]

posting this on the snooker thread last week but it got pushed down the page so ill pop it in here for a response.....

The match at 310 is just a smoke screen, seen it happen on the horses too lately, its someone who's trading that market and wants to get an edge. Just notice how the graph on Ronnie on Betfair no longer shows the price movement because of the high match right at the start. Now someone, ;) , making his own recording can discard that early price match and still see exactly how the price has moved over time. Quite an advantage for someone only interested in trading the market.

i dont get it ... what do you mean here data? how would this help anyone? am i being thick? cheers DC

[mr onemore]

Re: Self matching of prices on betfair Yeah - I saw this on that thread too. Quite clever really...normally when you look at the history of bets in a market the graph gives you some indication of how th market is moving - a lot of people like that info when they're putting on a bet. Thing is you can really distort the vertical scale by posting and matching a MASSIVE bet compared to the normal ones. After that, the graphing software scales everything down and just shows one big spike to represent the big bet. After that, anyone betting just has no idea what the market has been up to unless they've been folloeing it really carefully. The advantage is that after doing a slef-match, you might be able to get another normal sized bet matched at odds that didn't look so attractive before. I think that was the gist of the trick anyhow...

[Datapunter]

Re: Self matching of prices on betfair :lol think about it for a moment, how many people look at the graph on Betfair to see how the price has been going ? with the intent of either backing or laying anticipating the next move of the price. now suppose you get on right when the market opens on Betfair, and you match a very high price, with your own account, so back and lay yourself, say at 500.00 that will show as a very big spike on the graph, effectively rendering that graph useless cos all the little spikes at 2.00 or 10.00 just aren't visible. now who would benefit from such a thing ?

[Datapunter]

Re: Self matching of prices on betfair hello, posted the same time as mr. onemore, also up late i see :ok and no David, you are not being thick, just put your thinking cap on.

[mr onemore]

Re: Self matching of prices on betfair Just posting a few spikes up myself !! :loon

[Tulenos]

Re: Self matching of prices on betfair A bit of a similar move appear during in-running betting, the rpime example being for instance last nights match (MAnU v Ch) after the third goal was scored the no goal market reopened with layers offering 2.5 and backers wanting 2.9, so it stayed put for about one minute or several seconds, all of a sudden there was a quick exchange as those 2.5 appeared on the backing side for a blip of time and was supposedly fully matched - then back to normal 2.5 - 2.9 which stayed for another minute - guess how much was match at those "offered" 2.5 (for cca 1 second or so) - NOTHING - it was just a shrew move to invite some backers to that lower level - the actual odds then settled at about 2.7 and were going down of course but not that early. Happens each and every match or in most of them, when there is enough liquidity.

[Lizard7]

Re: Self matching of prices on betfair Can't help with the above, only another thought. There is no scale on the time axis, which I have always though would be useful. Do you think that by making a trade as you describe, they are able to attach a time to it?

[DeepBlueDevilFish]

Re: Self matching of prices on betfair Some of the antics in the In-running Betfair markets have to be seen to be believed. There was a horse race the other day (the 8:20 @ Windsor Mon evening) where 2 or maybe 3 of the horses refused to start but Betfair didn't have time to reform the markets before the race went "In-running". Some of the trading that then went on was absolutely crazy. I couldn't make head nor tail of it because I didn't know those horses had been withdrawn. Of course all the matched bets on the withdrawn horses would have been voided but I think what people were doing was to try and confuse the hell out of the bots. People have these set up to milk these markets and by artificially inflating the prices of the horses that are running (by trading on the ones that are not) it *might* have been possible to make a tidy profit. I don't pretend to understand it all, there are far cleverer people than me doing this sort of thing on Betfair. But I have seen enough to know to take great care on these markets and not to jump to any hasty conclusions about what's going on from prices changes and price graphs etc.

[Datapunter]

Re: Self matching of prices on betfair Tulenos, what you describe is not the same but simular. Its a tactic used by traders to gain an edge. In stead of guessing if the market odds will go up or down they actually try to make the market go a certain way. Lizard7, i'm not sure but it appears to me that the timescale of the graph on Betfair is logarithmic. This means the information is continually compressed towards the left side. It is a fairly normal procedure used when displaying long term information in a graph. When you look at the graph then on the right side you always have the most recent info. Let's say 10% of the right are always the last 10 minutes. On the left side you have the info from the past, let's say the 10% of the graph most on the left contains everything from when the market opened up to half of the total duration of the market. This is why, as time progresses, you see the graph compressing and gradually losing precision. More and more info from the past gets compressed in less and less space to the left. DeepBlueDevilFish, i can follow what you describe. Bots are here to stay and in terms of trading it really is dog eat dog. So your assumption of what goes on is probably quite close to reality. I have the bits and pieces needed, speaking as a programmer, to create a bot. But i haven't actually made one yet ;) . I'm afraid i lack the ruthless killer instinct :cry Then again, never say never :dude

[Datapunter]

Re: Self matching of prices on betfair back to the original question, the spike making the graph useless. who would benefit from that ? For some time now betfair can be accessed with their API. That means you can access the database direct using programming of your own. And these days there are a few commercially available programs that allow you to bet on Betfair using a specialised interface. The ones using the API are officially supported by Betfair, that means the developers get supported and there is some guarantee from Betfair that the API will work and continue to work. It's also possible to do it without using the API. This is done by accessing the website and not the database direct. Developers get little support from Betfair and its is quite possible that if Betfair changes the site, those programs no longer work ! Then there are a few 'amateurs' out there, ( like me ;) ) , who have developed software like this for their own use. Either way, all these programs allow you to create any type of graph yourself. Now then if you can see how the odds have been going, and the general public cannot, is that an edge ? You bet it is.

[mr onemore]

Re: Self matching of prices on betfair

Lizard7, i'm not sure but it appears to me that the timescale of the graph on Betfair is logarithmic. This means the information is continually compressed towards the left side. It is a fairly normal procedure used when displaying long term information in a graph. When you look at the graph then on the right side you always have the most recent info. Let's say 10% of the right are always the last 10 minutes. On the left side you have the info from the past, let's say the 10% of the graph most on the left contains everything from when the market opened up to half of the total duration of the market. This is why, as time progresses, you see the graph compressing and gradually losing precision. More and more info from the past gets compressed in less and less space to the left.

Ah - now that's very interesting Datapunter - as I thought that you couldn't make any inference about the time (horizontal axis). I had the feeling - no data to back up Im afraid, just a feeling - that every bet, regardless of magnitude, took up one unit/pixel on the horizontal axis. So that 20 bets of $2 placed quickly one after another would make it look like a large time-scale had passed, when in fact it hadn't. I hope I'm explaining myself here. If that was the case of course, you could make no inference about the time-scales as they would be non-linear, and in fact quite random. I suppose there are quite easy ways to test this - but I'd like to know now, as if it is as you've described there Datapunter then there's info I'm not using/not aware of..:eek Interesting discussion....

[Datapunter]

Re: Self matching of prices on betfair i can follow that mr onemore, The closer you get to the closing time of the market, the OFF or kick-off or whatever, the more bets are placed. This natural increase in activity is a possible explanation for the compression the graph makes. I'm making my first steps trading on the racing, so this is one of the questions i'm looking to answer. Think i'll dust off some of my old programs and see if i can get to the bottom of this. To be continued....

[mr onemore]

Re: Self matching of prices on betfair Well good luck there Datapunter - I'd certainly like to know the answer to that one when you find it...:ok

[Tulenos]

Re: Self matching of prices on betfair Just a note, Data - the fifth word in my post was "similar" and I also posted it as a similar kind of making the market.;)

[Tulenos]

Re: Self matching of prices on betfair Anyway, a very interesting read this thread indeed.

[Datapunter]

Re: Self matching of prices on betfair right, sorry, :o

[davidcampbell]

Re: Self matching of prices on betfair ah thanks guys kinda obvious i suppose now that i think about it.

how many people look at the graph on Betfair to see how the price has been going ? with the intent of either backing or laying anticipating the next move of the price.

you could roughly get similar info based on quantities of money sitting on either sit of the back / lay divide could you not? yes it wouldnt be quite as useful but it would do a job to the extent of giving an indication of where the market is going next ..... ?? or is that too simplistic

[SecondSight]

Re: Self matching of prices on betfair I have noticed the average betfair punter is getting a bit cuter of late on UK football.At one point I felt I could get better value (accounting for commission) on Betfair for the majority of my bets say 80%, now its less than 50%. I use the graphs and figures to the right as rough guides, however I tend to carry a price in my head of what is value based on my own opinions, other informed punters and those of the bookies, especially the smarter bookies so game playing hopefully does not fool me. I've noticed Ladbrokes are waiting until Thursday am to post their prices for the weekend and I am sure they are watching the Betfair market. 24 hours before a game is interesting as new money and punters seem to come in. I have a feeling these are not quite as cute punters. Last week money seem to be coming laying Boro, on Friday evening, I could not understand this at all, Spurs had lost Robinson and Boro gained Schwarzer. I can only guess it was Spurs fans money which pushed the Boro price upto 2.5 (6/4) based on a 5-1 home win over Villa. This was a big buying opportunity, but I had already placed alot of bets on the game so I left it. There is red herring info floating about that changes the price, this is crucial to know, say a player is out, which most people think affect the team, but if he is no good it does not affect the outcome, but the price rises on the team and its a buying opportunity. Bookies are not so keen to change prices, but the betfair price by its nature is changing alot. In the last month I have put my price in that I want, if its taken great, if its not its void and I have lost nothing. Apologies for a bit of a ramble.

[Lizard7]

Re: Self matching of prices on betfair DavidCampbell - you would think that, but don't forget about the bots. I have seen thousands matched but only ever a couple of hundred showing at a time - if you get me.

[davidcampbell]

Re: Self matching of prices on betfair hmmm yeah good point lizard