When inventing a system....
 

OK here's one for you all.

I love reading the posts on this system part of the website, because systems are great. They're the promise of the pot of gold, the holy grail, the "discovery".

"EUREKA!" you cry as the set of results come in and it's in profit.

Then comes the dreams of sitting on a yacht, sipping champagne as you listen to your bets roll in, and of course the obligatory large mammoried blonde reclines next to you.

That is - of course - the illusion.

But I did read with interest the thread on the 4yo system recently, and it occurred to me, what's a good sample size for a system?

If for example you find a system that's winning 20% on turnover, then you're flying, but how reliable is that 20% for future forecasting? How many selections do you need in your sample size to be able to confidently say that the trend will continue?

Also, if the dividends of a system are calculated from SP, what improvement can one expect when using a variety of methods and choosing the best in the real world, ie products like maxi-div and best fluc and betfair and austote. If you're in front of your computer ten minutes before a race and you have all those at your disposal (though admittedly top fluc is not available ten minutes before), then surely you're going to average better odds than just SP.

Thoughts, peoples?

Undoubtedly the bigger the sample size the more confident you are of your results. My system which just covers WA is based on results from 1997 to present day and the fluctuation on a year to year basis is 97.2% returned for 1998 to 112.8% returned in 2002 (Based on Tabcorp prices).
This means if for example I had tried the system out at the end of 1998 I would have binned it as useless because it had a slight negative return - and that would have been based on over 3000 bets.
As my system chews through the data it updates the percent returned on screen after each race and the (rapidly moving figures) for each year shoot up and down wildly for the first part of a year, they can even move about quite a bit as the year being processed nears the finish. This just illustrates to me the clustering of wins and losses and convinces me that anything less than a couple of thousand results (unless you are showing a very significant win or loss percentage) is pretty meaningless. My system is based on form and selects a lot of favorites so I'm not talking about a system that is relying on a few long priced winners.
When I started using real money about a year ago, the first week I lost 7 out of 7 races but because I had over 7 years results behind me I never doubted it would come back to profit. The more data the more confidence you can bet with.

With regards SP versus other divvies. My system returns negative 0.8% on SP over the last 8 and a half years and positive 5.26% on Tabcorp. I don't know if that's typical or if my selections are just closer to bookies selections than Tab ones. On maxidiv which is where I bet at present I'm laughing. Nothing like hearing a horse pay $5.00 when you listen to the race on the radio and seeing you got 7 or 8 next time you fire up the computer.

KV

Thanks for that Kenny. Very informative.

The reason I put this post up is because I have been researching a bit of a system using my ratings, and over a roughly one year period there have been 320 selections, strike rate of 30%, ave div SP of $4.60 POT of 40%!

So, is 320 selections over about a year enough to get excited about?

It certainly is a promising beginning and I'd be feeling pretty good about it. But is'nt the answer to your ponder, how long is a piece of string.

As time goes by and your system continues to roll out profits consistently you must have confidence, but it could still show a negative, even it is just one year. Just sit down and hold on for the ride.

What else are you going to do?

Good Punting.

Yeah good point Top Rank. Your insight is, as usual, spot on.

For the record I thoguht I'd give it a crack today, looking at selections in advance for the first time. Today there were two, for one winner, paid $3.00, so I made a profit. If I replicated today's events exactly every single day I'd be a billionaire.

the maths
 

Hi Duritz
The first thing you should do is work out your "Difference between Win % S/R and the Win % S/R that will yield your Min Edge which is normally approx. 10%.
The formula for the above is Your Win%-(2+(2*Min Edge(.10)))/ avg payoff (to compute this avg payoff do the following (2*your avg payoff($3.60)+2.
based on your figures this should equate to 6.09%.

Now to find the minimum number of races computed to a confidence level of 99% do the following.
(your Win % * your Loss %)*(2.575/.0609)^2. the answer would be 376 races to provide you with a 99% confidence level.

Good Luck

Woof I used to think I was pretty handy at maths at school. Did 3 unit but I don't like to boast. (Is saying 3 unit dating myself?) Anyway that stuff that you just threw on there is way above anything I can handle.

I am happy knowing what I am doing is working and that the profit is there.

Duritz I am surprised. A savvy dude like you, your aiming way too low. A multi billionaire is the least you can expect. Good luck with that maths.

Thanks Woof, Top Rank.

The first part of your post, Woof, working out the difference between s/r and s/r required I did the following:

To make 10% profit, (minimum) return is $110 for every 100, which is a s/r req of 100/4.6 or 23.91%, making the difference of 6.09% that you talked about. So, got that bit right.

For the second bit you said:

Now to find the minimum number of races computed to a confidence level of 99% do the following.
(your Win % * your Loss %)*(2.575/.0609)^2. the answer would be 376 races to provide you with a 99% confidence level.

wouldn't that be therefore:

(0.3*0.7)*(2.575/.0609)^2

or

(0.21)*(42.28)^2

or

8.879^2

= 79 or so?

Which bit did I muck up?

In excel
 

I wrote the formula thinking you would input it directly into excel.
=sum(.3*.7)*(2.575/.0609)^2 the answer will be as I stated.

OK well I have done some more research, and now the number of selections is co-incidentally EXACTLY 376! Complete accident too, just said, "I'll research to this point then check the answers", and it had gone up to exactly 376 selections, which Woof said was the number I needed for a 99% accuracy level.

SO, here's the results after 376 selections:

selections - 376
wins - 116 (31%)
collect - 518.70
average dividend - $4.5
profit on turnover - 38%

Does this mean I can be 99% sure of the method holding up? Or something else? What does it all mean?!?!?!

Obviousy with that maths stuff up by me there I musta bod when I should have mas, or vice versa, or something.

Yeah my problem was I raised the whole thing to the power of two, when I shoulda raised the last bit to the power of two then multiplied that last answer by the 0.21 at the start.

So, I actually did Mas when I should've Bod.

Hi Duritz!
It's especially embarrassing when we know how good you are with parentheses!? LOL.
Missing the fact that only the last bit was to be raised!
Tsk, tsk. Where is the world coming to?
Cheers mate as long you are winning that's what matters!

Duritz,
The last time I tried to raise the thing to the power of two I found I wasn't up to it so I did Bod by himself and Mas really got upset.

Sorry mate couldn't help myself ( ************ chardonny again ).

ROFL brilliant stuff, sexual innuendo in maths!

Duritz, I feel like a wilting violet amongst all this grey matter, but if I can put in my 2c worth in (laymans terms), I've hit the holy grail (thinks) several times, some involving thousands of bets and the POT always hovering, until inexplicably an exceptionally bad run is encountered, which of course I tried to ride out,... "confident" that the roundabouts were imminent,...... unfortunately on several occasions they never arrived. Although the same plan from then on continued to make a profit, but not enough to absorb the losses.

At the moment I too have 3 plans on the go (one for more than 2 years) all well in the black, but because of previous experience am still not game to call any the "Grail"

What it has done; is planted a seed ,that what is needed is to make a killing when all goes well and ride out the bad times when it doesn't, and if AFTER all that there is still a profit,.... we have done well!

Thankyou, PartyPooper, I am now firmly back down on earth, miserably waiting for my system to fail.

I'll just go prepare the noose now too.

Hey from the point of view of stats, what do you all think of this system's results? This is one I was testing simultaneously with the other one. Again, about a year worth of results, these are the stats.

Selections - 2500
Winners - 581
S/R - 23%
Collects - 2490
Pot or Lot - 0%


THAT is on SP. SO, using other methods, that could become a POT pretty easy. Is 2500 a good sample size?

Partpooper are you saying that you had a system that showed profit after 2-3 thousand bets and then still had a bad enough run to send it spiralling into negative.

I don't want to think about it.

Top Rank, no not quite, but it devastated several "banks" and decicrated (spelling?) ALL confidence, although I have since re-commenced the basic idea but with safety measures, but still proceed with caution. When youre place betting showing around 4-5% POT (overall) as duritzt rightly says you can isolate any group of 2,3 ,4 or5 hundred bets and show vastly different figures.

Duritz.

Sorry mate I wasn't trying to be a "partypooper" I was only telling "my" story, you may well have the Goose firmly in your grasp, good luck!

Hi Duritz,
Pleased to see you've grasped the nettle at last. Or are you having a sly dig at sytemites?
First you say that systems are great, something of an about face from most of your previous threads, then you tell us we're dreaming or at least our prospects are illusory
And do you think that all systemites share the juvenile fantasy you have described? And if so, why only systemites? Do you equate us with the glossy brochures from the Gold Coast? I've never seen any posting from from you telling form analysts that they are chasing such pie in the sky.The inference being that you think more serious and dedicated form analysts have loftier ambitions maybe?.
Anyhow, be careful how you play with your systems. You just might get hooked.

p.s. If you need a hand with the champers or the blonde (while you're doing the form perhaps), I'm your man.

Fox don't get me wrong - I love systems. Always have. I love them because they offer fresh hope if you've had a losing day. You can go from being miserable as your get out in the last hides away in the back of the field to being ecstatic at about midnight that night as you are still up, swigging vodka straight from the bottle, wearing just boxer shorts and endlessly tweaking the rules.

I love systems because they are the promise of SOLVING IT, of BEATING it in one fell swoop.

I love systems for these reasons and always come back to inventing them because frankly it's fun, too. I love systems, I have just never actually believed they can win.

Doing the form is such a grinding way to win compared to them. Don't get me wrong, I love doing the form too. Tonight I thoroughly enjoyed doing full form for three races at Ballarat tomorrow which I will be value betting. I enjoyed the challenge and the thought process involved, but the yin to this yang is the system, where you don't have to think of the horses each as individuals and know what they can do and can't do.

I love the form when it works out, too. Like on Saturday I had been busy on Friday and wasn't that keen on Flemington anyway so just did Makybe Diva's race only, in Sydney. She was an absolute certainty for mine, and after I examined each runner with my weight ratings applied, it bore it out. Over 2400m, she was a certainty. Over 2000m, Grand Armee would've been a certainty. This is something a system could NOT have grasped, but of course the mind can.

I think overall I love systems because if you find one that wins it means you can have that most lovely thing - a daily punt - without having the endless grind of form. Trust me, you don't want to do the form every day. I love the form, but really try to restrict myself to just Wed and Sat (plus specials like public hols) so I don't burn out. When I do go and do too much form I get sloppy and end up LOSING on badly made bets. When I stay fresh I do the form RIGHT and I WIN because of it.

But I do like the daily punt, even if it's just a smaller bet on a couple of chances that a system throws up. That's why I try to find one.

As I said in another post, my grandfather used to keep piles of the Sporting Globe and would be endlessly going through them to try and find a winning system. He was no mug, either. In Phar Lap's Melb Cup he had $2000 pounds on the great horse at something like 8/11, won about 1550 pounds. Work that out to todays currency with inflation etc. He bought a mansion in Toorak from that.

But he never found the pot of gold sys. My old man has spent much of his life doing the same. I don't want to be that way. I do firmly believe that to have an edge long term you need to do the form properly and - VERY IMPORTANT - bet properly.

With that in mind I sort of expect this system I have invented to fall over. However, it has something going for it - it is based around my weight ratings. They are great ratings and are obviously not something anyone bar me (and my wife should she wish to use them, which she doesn't! and my 1yr old girl, who isn't yet saying "quinella" or "trifecta" but will) has access to, so that angle and edge may enable them to win.

At any rate, I am going to bet the selections it throws up, give them their chance. Mind you I won't be outlaying as much on them as I do on my value betting though. But, in time, should it continue, who knows.....

At the time of writing, the research I have done on them, using SP prices, comes up with these stats:

selections - 407
Winners - 129
s/r - 32%
collect - 620
profit - 213
%pot - 52%
ave win price - $4.80

As I said, that's on SP. So, over that time, even just say betting maxi div I think the POT would be higher.

Maybe it'll fall down. I'll find out because I'll give it the great test run - with the dollars down, the chips in.

G'Day Duritz,
I think I might have a clue for you as to why your systems keep falling over.

Maybe you should try Y-fronts, earlier in the day and whisky not vodka. And if that doesn't work I'm right out of ideas.

I must disagree with you about a system not being able to pick Makybe Diva to beat Grand Armee. Just off the top of my head how about in a 2400 race backing the horse that has won most money at 2400 or further? I guarantee that using that simple plan MD would have been an even bigger cert than on your weight ratings.

Anyway, I have another system that needs some attention so I'm off to find a bottle and change my daks.
Happy punting.

How about shortest priced or highest rated horse that had been placed at the distance of today's race. Or any horse placed at today's distance which had won it's last start exactly 7 days ago.

My only issue with mechanical systems is that they tend to focus on what a horse has done in its previous starts rather than comparing its performances relative to other horses in TODAY's race.
As an example - if today's race was a 1350m race at Doomben and your system rules included (say) "winner at track and distance". The system would select a local horse. Unfortunately that sneaky Mr Hawkes had shipped up Lonhro for the race - never raced at 1350 or at Doomben so would slip through the filters. System falls over.
I guess that's where judgement rather than blind acceptance of the system output comes in.

Yeah OK so systems could get MD over Grand Armee, but in those examples b/c GA hadn't started at the distance. What I mean is, it took a little bit of insight to say MD will love the extra 400m. If RoboAnalyst looked at MD he'd say "Beep Beep, she won G1 Australia Cup over 2000m, beep beep, she is at her best therefore at 2000m, toot." But MD didn't do her best in the Aus Cup. Her best is clearly 2400m+ but RoboAnalyst would say she is equally good from 2000m-2400-3200, b/c she has won G1's at all of them. (Beep toot).

Zorro I agree with what you said to an extent, which is why I have fashioned the rules of this one around my weight ratings, meanign the horse has to be good enough to win in order to qualify. "Hapless slug" ridden by "I.M.Useless" may have won a c1 at Rosehill on a wednesday on a heavy track against three other slugs, unnoticed, by a lip, and they were all stuffed at the end, and the owner may have entered him in the Grand Armee v Makybe Diva matchrace over 2000m at WFA last weekend, and as you say you'd be having your bet on Hapless Slug, because he's won at the track and distance. Well, not with my method.

But I guess you don't need ratings to do that. You can introduce some sort of class rule. Must have placed in the class or something. Must be pronouncable after three quarters of the bottle of no name vodka you're swigging from at midnight, standing in the middle of your study in your boxers yelling at the computer....

Duritz, you said:
a)"What I mean is, it took a little bit of insight to say MD will love the extra 400m."

How much insight did it take? Not a lot. Everybody and his dog was on MD (apart from super optimists who still think a Sydney donkey could beat anything from Melbourne) and there have been 4 off the cuff examples of the simplest sytems that would pick MD.

b)"If RoboAnalyst looked at MD he'd say "Beep Beep, she won G1 Australia Cup over 2000m, beep beep, she is at her best therefore at 2000m, toot.""

Have to disagree again. Even on a bad day in boxers and lubricated with vodka RoboAnalyst would say that MD was best at 3200, better than GA at 2400 and almost as good as GA at 2000, depending on how he was programmed of course.

Seems to be my day for disagreeing with people.
Do you mean that because the system did not pick the winner of that hypothetical race it is useless?
If so, the simple (and eminently sensible) filter of not backing your pick against odds on pops would fix that. I realise that you are hyperbolising when you use Lonrho for your example but there are many other filters that could be applied and nobody expects his system to pick every winner anyway.
I'd gladly settle for one loser per day every day as long as I could have two bets.
Cheers.

ZORRO.
 

I know where your coming from.
Its how your horse is rated against other horses in TODAYS race.
An example is XPTDRIVERS ratings in another thread.
Cheers.
darky.

Foxwood,
I was not suggesting the system would be useless - just that blind acceptance of any system's selections is risky.
I could even debate your suggested extra filter of ignoring a selection opposed to an odds-on favourite. It may well be a false favourite and the system selection may be a great bet.
As I said before - it's a judgement call.

Quite simply using a price filter takes care of the opposition.

The market being the best guide to a horse's chances, a horse with the same qualifications may start at 20/1 or 5/1 in different races, the price reflecting the class of the opposition.

OK I've created a monster here.

Thing is, what I was TRYING to say - and I think zorro was alluding to - was that mechanical systems can never take the place of common sense, and no matter how much you put in rules like "don't bet against odds on favourites" etc, they are nothing more than polyfilla to fill the gaps left by virtue of the fact that rules cannot think for themselves.

There are a BILLION systems which post the event could come up with Makybe Diva, like third letter K for example, or back the horse in the race who has two names, both with even numbers of letters. Not disputing that systems could come up with it, what I was really trying to say is that the capacity for the human mind to be creative and think creatively far outweighs the capacity of a set of rules to do same.

Mind you, with that in mind I started this thread because I do love systems, and I seem to have found one with a werribee sewerage farm's worth of promise, and since I began putting money down the other day it has had six bets for three winners, POT of 95%. So, at this point, I am rapt, and don't go anywhere I may just be a system convert if this keeps up.

Mind you, I know it won't, am expecting it to fall over at any point, systems can't win, touch wood, salt over the shoulder, cross myself.

Duritz.

PSSSST, don't forget the 3rd letter "R"

Mind you I am possibly blurring the line by what's a system and what's not. Considering my "system" is rules applied to my ratings, is it really a system or is it a systematic form of analysis?

Where's the line?!?! IS there a line?!?!?!?!

We're through the looking glass here people....

I'm a dedicated system player.

I'm not a form analyst.

System players look at chunks of data and determine something that works longterm. Providing there is sufficient data to support the theory, one then tests it in realtime. There is no reason that the system should fall over.

UNLESS:

Reason 1. There was not enough data to begin with.

Reason 2. The rules were so tight or so many, that it gave improper results.

Reason 3. All the profit comes from one or two winners.

I'm amazed when I see systems with more than about 5 rules maximum.

To test the validity of any rule, simply apply it on it's own and see the difference - you'll soon see that half the rules imposed on systems are more about grinding out a profit, rather than seeking one. (retrofitting).

On the other hand we have the nitpickers (oops form analysts).

They tend to disect each race, each runner, each piece of garbled form and rate or pick the best contender.
They have a far greater understanding of the mechanics of racing, but the challenge is to get value. The problem being that the public favourite will more often be their top pick than not, otherwise their analysis is wrong! (in terms of longterm results).

An analyst may be influenced by other factors, but I believe has a greater chance of picking the winner of race A than the system player, but longterm the system player has a better chance of making a profit providing his data has enough substance to it.

Don't want to stir up trouble, it's just my view.

LOGIC APPLIED TOO.
 

With any system I have come across (and I have over 250 of them) too much logic has been left out and really needs some further analyisis.
For example .In short distance races a set of system rules may point to horse A but going deeper in the analyisis you may find the horses normal racing pattern is as a backmarker with the highly liklleyhood of being checked /blocked /having to race wide etc etc

Hi Darky,

Yes many commercial systems are retrofitted like hell with very strict rules for many of them. Then they are marketed and almost always fall over.
Not because every man and his dog (excuse the pun) are using them, but because the rules were flawed to start with.

Then the common misconception becomes "systems don't work". Only because the marketed one's either don't have enough data, are based on one or two longshots, or are put in a vice to squeeze out what looks like a good result.

Glossy brochures rarely give a FULL breakdown of system performance, nor do they tell you if you take out the two longest priced winners, it shows a loss.

The little system we talked about off forum continues to show profit and you can take out 20 of the longest priced winners and still show a profit.

;)

What was that one? What was it? Tell us! Tell us! Aaw go on, tell us! Aaw, you're mean....

Duritz,

Yeah guess it was a bit mean of me, but I can't post the rules because it's a system which people pay good money for.

It's based around fitness, form and market price.

I.E. Very fit, very good form, well in the market.