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mathare
1st April 2007, 22:30
I recently came across a few systems in a new gambling publication and they struck me a great examples of how NOT to create a system. The figures look quite impressive I'll admit but then they would when you see what the system creators have done.

I'm pretty confident I'm doing nothing naughty here as the systems are already in the public domain as they are printed in the latest edition of said publication. I have paraphrased as necessary to avoid copyright issues.

The magazine (who will remain nameless for now as there is no need to either promote or embarrass them) lists four systems, one for each of the courses they are covering in detail. I shall list the system rules for one of the systems and give the summary stats before offering my opinions on why this is the wrong way to go about things.

System 1

Redcar only
Fav with SP of evens to 11/4
Flat races exc 1m and 1m1f
2-15 runners
Soft, good or good-firm
Exclude selling stakes
Not Wednesday or Friday
Not March, August or November


33 winners from 76 races (43.4% SR)
124.8% ROI at SP

24.8% profit may seem like a decent return but take a look at this system in more detail. The key to system building is to find a profitable trend and to exploit it. These rules look like they have been fitted to the data and as such any profit is more likely to be coincidence than anything else.


Redcar only - I don't have a problem with this rule. Some trends show up better at certain tracks. However, it is worth noting that when building a system the performance at each track should be considered a filter rather than a major rule. That is you should be looking to identify a trend that makes sense for all racing and then see how the profit breaks down by track. It may be that for some reason some tracks don't fit the trend as well. This may be down to the course characteristics, e.g. galloping, undulating, left-handed etc.
Fav with SP of evens to 11/4 - concentrating on the market leaders is not an unusual ploy. But including SP in the rules is a rookie mistake. Starting price is not, and can not, be known until the race has started. And you can't generally back a selection when the race has started. If you need to use a indicator of the market either compile your own forecast odds or use those provided in a newspaper or online at Sporting Life or Racing Post. You can't include SP in a system rule.
Flat races exc 1m and 1m1f - these distances are odd ones, normally systems apply up to a certain distance or beyond a certain distance. To exclude the 1m and 1f races strikes me as baffling, unless there is something strange about the part of the course over which these races are run. The course is a left-handed oval of just over 1m with a chute providing a straight mile. So perhaps the problems arise with that straight mile and races run once round the oval. I dunno. But it doesn't sit comfortably with me.
2-15 runners - less than 2 runners and you don't have a race but you don't want fields to get too large. OK. Of all the rules this is probably the one I have least problem with. Horses can run into a lot of trouble in big fields so this one at least makes sense to me.
Soft, good or good-firm - using the going as a filter is not a problem, but the chosen goings are a little odd. Soft is OK, good is OK, as is good-firm. But not good-soft so why not? System rules should quote a range of goings because the official going is often slightly wrong. Soft ground may be riding good-soft, for example. But that throws this system out of line. Had the rules stated the going had to be soft through to good-firm I would be happy. Not too muddy, not too fast with plenty of scope in between if the official going is slightly out. But that's not what it says, and that makes me wonder how this rule came about.
Exclude selling stakes - some trends are not seen in some race types. Maybe it's the quality of the animal running in them. This seems a little too specific though. Claimers are OK, as are maidens. But not sellers. And a selling handicap would qualify. Does that not strike you as odd?
Not Wednesday or Friday - and now we are in to the plain ridiculous. Redcar hosts 17 flat race days this year. There are two Wednesday fixtures in that lot and two Fridays. That rules out nearly a quarter of the meetings already. And the rationale behid this rule? God only knows! One day has to be the most profitable for this system, so it stands to reason that some days will be less profitable. But does it make sense to miss certain days of the week out? An annual race run on a Thursday this year will be run on a different day next year. Is that any reason for it not then to qualify. This is just nonsense in my opinion.
Not March, August or November - not the start of the season (March) or the end (November). I'm fine with that. Horses running early season may be run to get an idea of how the rest of the stable is shaping up. Or they may be running just to get a run into them. At the end of the season a horse may be run for one last shot at the prize money before it is retired or put away for the winter. But August? If anyone can explain the thinking behind not following a system in the middle of the season then I am all ears.


The notes for this system say that 2006 went against the profitable trend but the law of averages says this should average out and following these stats should produce winners, expecially in handicaps. I say hogwash!

What has happened here is someone has analysed the Redcar data and looked at how to produce the best profit from the data available. Horses have steadily been eliminated by applying filters as rules without thinking if the rules make any sense any more. This is something the human brain is prone to - fitting trends that don't exist to data it doesn't actually fit. This is only one step removed from having a system that says don't back any losers.

The systems for Thirsk, Ripon and Catterick are similar piles of poo.

I have no idea how many years have been analysed to build these systems (I suspect it is 2002 to 2006 based on other data in the article) but 76 qualifying races isn't many is it? When paper trading the general advice is to try and get a couple of hundred qualifiers under your belt before you decide whether or not it's working.

As I said earlier, I am offering this up as an example of how not to create a system. The trend is artificial, created by filtering the data to maximise the profit. And the authors even admit it made a loss last year.

There are hundreds of systems like this out there on the internet, especially on Ebay. You'd be wise to take each and every one of them with a pinch of salt. Before taking on a system look in detail at the rules (if available). Do they make sense or do they smack of having been drafted to fit the most profitable runners? Look at the stats over several years and pay attention to good and bad years. Is the system built on trends that still exist or has the BHB changed the rules such that the system is no longer profitable? Can you obtain a list of all historical qualifiers?

These are the sorts of things you should be thinking about when it comes to adding new systems to your betting portfolio.

wb
1st April 2007, 22:56
An excellent write up Matt, I must spread more rep around before giving you some for that. I'm spending a lot of time creating systems for the upcoming flat season, and come across 'false' trends all the time.

I gave the example somewhere else, where the commentators for the 49s draw ball said ' Ball 2 is a cold ball and has not been drawn in X amount of draws' :laugh Amazingly, people follow these 'trends' not thinking about the fact that one of the balls simply must be drawn the least.


I agree with pretty much everthing that has been said.

I've one example of a day of the week rule that may have something to it though:

I've created a Dettori/Suroor system and excluded some years while checking the variables. I then ran it on every year to make sure I was not 'fitting' it. Every single year on the particular rules I used showed a loss on Saturdays. It could be coincidence, but I also have a theory...

A lot of punters have Dettori as their favourite Jockey, and he has a lot of followers..... Way more people bet on Saturdays than any other day, so could the Dettori followers be pushing the value down on Saturdays? Another thing to note about Saturdays is that the quality of racing is generally better, so this has to be considered when checking the results.

mathare
1st April 2007, 22:59
I would generally give you that Saturday rule for that system, yep. I'm not saying the day of the week cannot be a factor in any system and as you can see you can justify your Saturday rule. It's when the day of the week is factored in for no reason other than it trims out the worst performing day that I object to.

It was your comment on the 49s drawn that reminded me to write this thread actually :)

bigcumba
2nd April 2007, 08:07
Good post there Mat, I was reminded about the comment Keith made a few times that the horse doesn't know what day of the week it is! That is definitely an overfiltered system if ever there was one. I've come across many like that through Racexpert - some folk produced systems with a 100% strike rate and posted them to the website.. one of them had 3 qualifiers in 3 years (at the time) worth of data :splapme . Needless to say the next one lost. I downloaded all the systems and probably binned around half of them immediately because of over filtering.

mathare
2nd April 2007, 09:02
It can be tricky balancing profits and filters/rules. But for me the best systems are simple to operate, profitable to SP on level stakes and use a set of rules that complement one another and make sense as a whole.

I do like to get my hands on system rules where I can though. In the past I have lashed out a couple of quid on Ebay to get my hands on an ebook of 80+ systems. They were all crap but at least it got me thinking about what is good and bad about a system. I'd rather pay a couple of quid for that learning experience than pick up a system being touted as a great money maker and lose a starting bank of say £100 on it.