Place betting system for the horses/Betfair

[Guest teeshappy]

Hi, Instead of trying to explain what I am trying to do, I thought I'd reproduce a thread from the Betfair horse racing forum that I started. Any input is appreciated. Thanks. dave b Posted by : dave b        27 May 19:51        If a horse is @8.00 on the win market in a 12-horse race, what odds should the place be if the first 3 finishers pay out. I know there are a lot of variables, so the price wouldn't be accurate, but does anyone have a simple calculation to work the place odds out? I've been racking my brains and using excel formulas, but my numbers don't add up. Cheers.dave b         Posted by : timmyg        27 May 20:40        traditionally about a quatre or a fifth of the to win odds.depends on prices of other horses in field and size of field Posted by : viper        27 May 20:44        12 runner handicap 1/4 the odds first 312 runner non-handicap 1/5 the odds first 3 Posted by : viper        27 May 20:49        2.75 12 runner handicap2.4 12 runner non-handicapbased on win odds of 8.0 (7/1) Posted by : Mr Ed        27 May 21:59        If all the horses are 7-1, then it is a 3-1 shot to be in the first 3.However, the chance depend on the relative chances of the othersEg....1/10, 7/1, 100/1 bar, would make your horse a big odds on chance to get in the first 3In an average sort of 12 runner race, it would be about a 5/2 shot Posted by : dave b        27 May 22:53        Thanks guys, it's appreciated. Just for the record is my calculation below correct for working out the place odds for a horse @8.0 (7/1) in a 12 runner handicap? (8.0-1/(12/4))+1 = 3.33 The reason I think it's wrong is because when I did the figures on a few races this afternoon, my calculations were showing that it would be profitable to lay every horse (which of course is impossible). I know it's hardly rocket science stuff, and I don't usually have trouble with stats, but I've got some major blisters on my brain trying to work it all out.Cheers.dave b Posted by : albatross        27 May 23:11        There are several systems available. A method that has stood the test of time is to look at the potential tote place dividend, and then add on a percentage to reflect the tote profit. What you end up with is the mid-price, above which you back and below which you lay. The bigger the pool, the more accurate the method. Posted by : dave b        27 May 23:17        Interesting point from Mr Ed: "However, the chance depend on the relative chances of the othersEg....1/10, 7/1, 100/1 bar, would make your horse a big odds on chance to get in the first 3"How would you work out the actual place odds of the 7/1 chance? It would surely be at big odds-on, but what would be value? 1/10? 1/50? I wonder if neural nets could sort it? Anyone tried? Posted by : dave b        27 May 23:24        Yes, Albatross, I've watced the tote pool too. But it's like you said it needs a large total pot to be accurate. I've seen some really wacky odds on the tote pool when there isn't much liquidity, but I would still say that the odds on the Betfair winner markets represent a more accurate way of working out the place odds. Posted by : dave b        28 May 10:26        Just had a look at the first race at Yarmouth today. Using my formula above I worked out the "expected" place odds (1st and 2nd in a six horse race). Also included the range (back - lay) at the moment for the place odds on the betfair place market: win odds, place odds, place range (back-lay) 1.58, 1.20, 1.20 - 1.21 5.60, 2.53, 1.94 - 2.24 7.50, 3.20, 2.08 - 2.34 22, 8.00, 3.30 - 7.80 40, 14, 8.00 - 65 160, 54, 10 - 240 The odds-on favourite place price corresponds with the current range on the place market, but horses 2, 3 & 4 seem to show that on the place market these horses should be laid. On some races yesterday, doing the same as I have done for the race above, it showed that all horses should be laid, which doesn't make sense. Anyone have any ideas? Posted by : speedform        28 May 10:55        try thinking of it this way , it may help or it may notwin price = 22 , from your examplean £10 each way bet would return £44 if the horse was only placed but your total stake is £20divide your total stake of £20 by the return of £44 giving odds of 2.2/1which is 3.2/1 on bf which is close to the odds offered in your example Posted by : speedform        28 May 11:08        using my way i have comeup with place odd of 1.96 2.15 3.2 5.4 17.4 for horses 2-5 Posted by : dave b        28 May 11:19        Thanks speedform. Your figures look more realistic. I'll have to have another ponder. By the way how did you arrive at the figure of £44? Cheers. Posted by : speedform        28 May 11:27        sorry dave made a small mistake , return should be £5422/1 divide 5 = 4.4 multiply by £10 part of eachway stake = £44 , total return £54£54 divide by total eachway stake of £20 = odds of 2.7 or 3.7 on bf

[Guest Weststander]

Re: Place betting system for the horses/Betfair Hi teeshappy, normally the place terms applied to the win prices offered by the bookies give a reasonable indication of the horses prospect of placing.If it offers any value it's usually when there's a big odds on shot & that's why many on course bookies then go "win only".Tough luck on the off course books who have to still bet each way on the race. It's also the reason you'll never find a bookie going each way on the Scottish prem unless the book excludes the big 2. Try this method,it seems reasonable to me but I haven't ran it past anyone to see if it's flawed(although you have to be a bit of a permutations master to go to 3 or 4 places & it's extremly tedious to calculate.) Let's say it's a 6 horse race(1st or 2nd for a place) First work out the prob of each horse winning.If you've got a true 4/1 shot ,it's fairly obviously 0.2 or 20%. Place terms are usually 1/4 the odds if there's no odds on fav.So it's 4/4 or 50% that it's placed. If it's 50% to place(come 1st or 2nd) & 20% to come 1st,it's therefore 50-20%=30% to come 2nd. You should end up with seperate probs for horses to come both first & second. Next work out all the permutations for the first two places given 6 runners. Horse 1 beats horse 2, Horse 2 beats horse 1, Horse 1 beats horse 3 etc... You know the prob that say horse 1 wins & the prob that horse 2 comes second so multiply the two probs together the get the prob of that outcome occuring. Do this for all permutations. Scale the probs up or down so that they total exactly 1. Add up all the probs in which the horse you're interested in is in the frame(1st or 2nd). And that should(might??) be it's true place odds. I've done it for your 6 runner Yarmouth race(using 1/5 the odds..iirc that's the place terms with an odds on fav.) & I get decimal place odds of; Horse one, 1.3 Horse two, 2.08 Horse three, 2.38 Horse four, 4.76 Horse five, 7.8 Horse six, 29 I think there's an idea in there somewhere :-). W.

[Guest teeshappy]

Re: Place betting system for the horses/Betfair Hi weststander, Thanks for your reply. Yes, I realised that I was approaching this from the wrong angle. For some reason I was thinking that the number of horses was a factor, when of course it isn't. I have made the calculations as you pointed out, 1 with 2, 2 with 1, etc, etc. I came up with the following place odds for the Yarmouth race: 1,10 1,96 2,57 7,28 13,14 52,25 I haven't adjusted for a 100% book (actual 102,15%). I'm now trying to put together a spread sheet to cover 3 places which is another ball-park altogether, there are so many permutations it's making my head spin just thinking about it (think I'll go to 20 horse fields to start with, then there's the 4 place perms to cover - yikes!). Thanks again.