Drifters and steamers

[Ferru]

Hi What do you all think about the best course of action as regards drifters and steamers? There is a school of thought that says that if a horse is drifting it isn't a sign of insider knowledge, but rather that the horse is the subject of hype and is undervalued. However, it is surprising how often steamers - particularly heavy steamers- go on to either win or to do far better than their original odds would suggest. Does anyone have any data showing what profit can be made from backing or laying horses because they are heavily drifting or steaming? Thanks Jeff

[Fatz]

Re: Drifters and steamers Here's some figures released by Betfair in 2005 basically claiming that backing all 'drifters' would return a profit and backing all 'steamers' would return a loss. Personally I'm a bit sceptical and intend testing data from one thousand races run in 2007 using Betfair's definition of a drifter/steamer. I'll post the results if/when I finally get round to doing it. Cheers, Fatz. http://www.betfairpromo.com/tactemails/camb1a.htm

[billydilly]

Re: Drifters and steamers Hi I have software to test this theory, but I am not sure its as easy as the link says. I tested this on 500 bets during 2006, and was blown away by the results (110% return i.e. a fortune at £100 stakes) but on the next 500 bets the whole profit went down the drain. If anyone have got a good theory on how to trade pre-off, then feel free to share, I can test the theories for you :) There must definately be ways to take advantage of the huge volatility in the HR markets

[Ferru]

Re: Drifters and steamers Hi Fatz It will be interested to see the results. Out of interest, how will you be obtaining the data, and what software will you use to analyse it? Jeff

Here's some figures released by Betfair in 2005 basically claiming that backing all 'drifters' would return a profit and backing all 'steamers' would return a loss. Personally I'm a bit sceptical and intend testing data from one thousand races run in 2007 using Betfair's definition of a drifter/steamer. I'll post the results if/when I finally get round to doing it. Cheers, Fatz. http://www.betfairpromo.com/tactemails/camb1a.htm

[Ferru]

Re: Drifters and steamers Hi Billydilly It would be interesting to explore what happens with drifters and steamers? Do you have data from Betfair itself, and if so what data do you have, ie all prices, prices at particular times, etc? Regards Jeff

Hi I have software to test this theory, but I am not sure its as easy as the link says. I tested this on 500 bets during 2006, and was blown away by the results (110% return i.e. a fortune at £100 stakes) but on the next 500 bets the whole profit went down the drain. If anyone have got a good theory on how to trade pre-off, then feel free to share, I can test the theories for you :) There must definately be ways to take advantage of the huge volatility in the HR markets

[Gingertipster]

Re: Drifters and steamers Horses become steamers and drifters for a variety of reasons. What connections say about it in the RP can effect a price. If Paul Nicholls is positive about one of his you can bet it will shorten, and the opposite is true too. If tipped up by a tipster such as Valuescope or Pricewise it will shorten. However, the vast majority of steamers happen when good judges realise a horse has a better chance of winning than its price indicates. For example a 7/1 shot, a punter needs to win 12.5% of his bets at 7/1 to break even. If enough good judges (or some bad judges with money) think at 7/1 the horse has a much better than 12.5% chance of winning, they back it. Eventually it will be forced down in price. Sometimes it reaches a point when it needs to lengthen a bit to find its true position in the market. Other times punters see a steamer happening and want to get on board, following the crowd, forcing the price down further. Conversly, an under priced horse will not be backed by many good judges so his price will drift out. Not being backed until it reaches a price the good judges think is worth taking. If a 3/1 shot is thought poor value (less than a 25% chance) by enough judges it will drift out. Betfairs statement about steamers and drifters is in my opinion unfair, as steamers are often poor value at the off time but good value at early prices. If they are judged at off time they will show a loss. The reverse is true with drifters. The trick is to identify a good value horse before it becomes a steamer, or after it has drifted. See my thread on How to make a 100% book (in At The Races section, page 2) for further information.

[Ferru]

Re: Drifters and steamers Thanks. On a related matter, if the Betfair price has drifted below the bookies' price, does this mean it's good to lay, because you're getting even better value than the bookies, or to back, because it may be that successful punters whose bookmaker accounts have been closed are placing the bets? Jeff

Horses become steamers and drifters for a variety of reasons. What connections say about it in the RP can effect a price. If Paul Nicholls is positive about one of his you can bet it will shorten, and the opposite is true too. If tipped up by a tipster such as Valuescope or Pricewise it will shorten. However, the vast majority of steamers happen when good judges realise a horse has a better chance of winning than its price indicates. For example a 7/1 shot, a punter needs to win 12.5% of his bets at 7/1 to break even. If enough good judges (or some bad judges with money) think at 7/1 the horse has a much better than 12.5% chance of winning, they back it. Eventually it will be forced down in price. Sometimes it reaches a point when it needs to lengthen a bit to find its true position in the market. Other times punters see a steamer happening and want to get on board, following the crowd, forcing the price down further. Conversly, an under priced horse will not be backed by many good judges so his price will drift out. Not being backed until it reaches a price the good judges think is worth taking. If a 3/1 shot is thought poor value (less than a 25% chance) by enough judges it will drift out. Betfairs statement about steamers and drifters is in my opinion unfair, as steamers are often poor value at the off time but good value at early prices. If they are judged at off time they will show a loss. The reverse is true with drifters. The trick is to identify a good value horse before it becomes a steamer, or after it has drifted. See my thread on How to make a 100% book (in At The Races section, page 2) for further information.

[Fatz]

Re: Drifters and steamers Well finally got round to looking at drifters and steamers for myself. First thing to do was decide exactly what to measure as obviously there's no universally accepted definition of the terms and I'm sure different people have different ideas of what represents a drifter or a steamer. I looked at 1029 flat races run within a six month period between mid-July 2007 and mid-January 2008. The races were taken at random except there are none included where the favourite's morning price was less than 1.2/1 (had no data for these races and an odds-on shot who's price contracts to an even shorter odds-on price isn't my idea of a steamer anyway). I accept that just over 1000 races isn't a massive sample but hopefully it's enough to get a pretty good idea of the situation. I wanted the results to be roughly comparable to the figures released by betfair so decided to study price movement in the last two hours before the race as they had, and used their way of defining what constituted a steamer or drifter. Therefore any horse who's price shortened by 5% or more of the total book was taken as a steamer and any horse who's price lengthened by 5% or more of the total book was taken as a drifter. For example if a horses price changed from 3/1 (25% of the book) to 2/1 (33% of the book) there had been a 8% move and qualified as a steamer. If a horses price changed from 4/1 (20% of the book) to 9/1 (10% of the book) there had been a 10% move and qualified as a drifter. Betfair make no mention of the effect of non-runners on a market and I don't know how they dealt with them. If a horse was withdrawn within the two hour period being studied and was trading at 20.0 or higher I have included the race because the effect on the prices of the remaining runners would be minimal. If the horse was trading at a shorter price than this at the time of withdrawal I have omitted the race. On occasions there had been a non-runner declared shortly before the two hour window and the market was disrupted at that time. In this event I took prices as soon as the market had returned to something like normality, ie. the over-round had fallen back below 105%. If betfair failed to take non-runners into account then their figure would contain false drifters and steamers and would be flawed. Anyway here are my results :-

	Runners	Winners	Strike-rate	Return to £1	%profit/loss
Steamers	345	81	23.50%	351.76	1.9
Drifters	302	48	15.90%	301.10	0.0

There's no great bias of backing drifters over steamers as claimed by betfair. On the contrary the lack of profit or loss from backing either shows just what an amazingly efficient mechanism the exchange market really is at assessing a horses chances by 'off-time'. The in-efficiencies are in the early market and backing the steamers two hours before the race would have shown a profit of £203.62 to £1 stakes and 59% profit on turnover (before commission). Hmmm, now how can I predict those steamers before they steam and those drifters before they drift ?

[Ferru]

Re: Drifters and steamers Very interesting. Out of curiousity, where did you get your data? Jeff

Well finally got round to looking at drifters and steamers for myself. First thing to do was decide exactly what to measure as obviously there's no universally accepted definition of the terms and I'm sure different people have different ideas of what represents a drifter or a steamer. I looked at 1029 flat races run within a six month period between mid-July 2007 and mid-January 2008. The races were taken at random except there are none included where the favourite's morning price was less than 1.2/1 (had no data for these races and an odds-on shot who's price contracts to an even shorter odds-on price isn't my idea of a steamer anyway). I accept that just over 1000 races isn't a massive sample but hopefully it's enough to get a pretty good idea of the situation. I wanted the results to be roughly comparable to the figures released by betfair so decided to study price movement in the last two hours before the race as they had, and used their way of defining what constituted a steamer or drifter. Therefore any horse who's price shortened by 5% or more of the total book was taken as a steamer and any horse who's price lengthened by 5% or more of the total book was taken as a drifter. For example if a horses price changed from 3/1 (25% of the book) to 2/1 (33% of the book) there had been a 8% move and qualified as a steamer. If a horses price changed from 4/1 (20% of the book) to 9/1 (10% of the book) there had been a 10% move and qualified as a drifter. Betfair make no mention of the effect of non-runners on a market and I don't know how they dealt with them. If a horse was withdrawn within the two hour period being studied and was trading at 20.0 or higher I have included the race because the effect on the prices of the remaining runners would be minimal. If the horse was trading at a shorter price than this at the time of withdrawal I have omitted the race. On occasions there had been a non-runner declared shortly before the two hour window and the market was disrupted at that time. In this event I took prices as soon as the market had returned to something like normality, ie. the over-round had fallen back below 105%. If betfair failed to take non-runners into account then their figure would contain false drifters and steamers and would be flawed. Anyway here are my results :-

	Runners	Winners	Strike-rate	Return to £1	%profit/loss
Steamers	345	81	23.50%	351.76	1.9
Drifters	302	48	15.90%	301.10	0.0

There's no great bias of backing drifters over steamers as claimed by betfair. On the contrary the lack of profit or loss from backing either shows just what an amazingly efficient mechanism the exchange market really is at assessing a horses chances by 'off-time'. The in-efficiencies are in the early market and backing the steamers two hours before the race would have shown a profit of £203.62 to £1 stakes and 59% profit on turnover (before commission). Hmmm, now how can I predict those steamers before they steam and those drifters before they drift ?

[Kanga]

Re: Drifters and steamers

....... The trick is to identify a good value horse before it becomes a steamer, or after it has drifted .........

Gingertipster has it spot on here. The best indication of price is the last price at the off - therefore a steamer or a drifter is only a market correction and the horse is now running at it's "correct price". You need to have taken a steamers price before the price drop to have a measure of value, only this way will you make a profit long-term. Just as a side thought - why do you think bookies advertise a steamer ?