Winners are lucky. Losers are unlucky.

That's a good point FAFH. I have a massive edge on ze horses and it's been going for at least the last 6 years, and to me it's pretty obvious yet it continues to rake it in.

Tbh with BSP and BOG it's only getting better.

Yeah it's quite amazing in all areas of life how things can be so obvious to a very few, and so invisible to most.
Your horsey edge sounds like a licence to print money.
But it will remain well out of my reach as the geegees are something I have never been able to fathom the complexities of. All those different classes, different weights, handicaps, distances, turf conditions, riding strategies, weather conditions. The list of variables is numbingly long and tbh totally unfathomable.

Sometimes I think if you weren't born with a parent or close relative who took you to the races early on in your life, and clearly explained a few of the basics, then you're probably never going to get into it as either a sport to watch or to gamble on.

I have had one losing month in six years.  I am not the lucky one out of a million bot operators, what I do has a very small edge to it which  wins over the long term.  For now. It may vanish at any time just like any edge on here.

A million bot operators ?
Really ?

FAFH?

You think I'm the consolidation of a million bots ?

FAFH got a couple of things to ask you if you don't mind buddy...

firstly, why did you name me and Schalke on that list?

Because quite simply you do not post in a manner that would indicate that you know how to win long term in the gambling arena.
I apologize if I have gotten this wrong and in fact you do.
If so, then please just start posting in a manner more indicative of this and all will be hunky dory eh  ?

fair play.

my second thing is, i would love to take on any "big hitter" (contrarian, bayes, investor) in a tip off and i disagree that they would, over time, be ahead. i think it's more down to betting style. your thoughts?

Yes you could probably be right in terms of a pure tipping compo.
But that is not what pro betting is all about, is it ?

exactly

Someone who is a long term loser is not going to beat a long term winner in a tipping contest of any meaningful duration

Unless the winner is only winning with fast pics or some other non skill based edge

Well they could win , but you would certainly not price it up anywhere near evens

1.2 contrarian 4 frimpong

ill
take
all
i
can
at
1.2
please

Well if Contrarian and frimpong were to enter in a tipping competition, Contrarian would have to write some software to post bets to the forum thread when they are submitted .

I think many long time winners here are using trading techniques which dont necessitate to guess who will win the match in the end. it's at least true for tennis, don't know for other sports.

They still need to know when the players are value, and presumably start with a value pick pre match and take it from there

I traded on Murray Ferrer this week. If i was in a tipping comp, i would have tipped Murray. Result, Murray lost in straight sets, but i won money on the match, because i followed some trading routines which work indepently of the final result. Odds are moving very quickly in tennis, you can win (or lose) a fortune in 5 minutes.

* independently

abolo
Most posters seem to be indicating that the only way you can make money on tennis is by trading in-play.
In fact I've yet to read a post on here claiming pre-match value picking success on tennis.
Are there posters on the tennis forum claiming to be able to pick winners at a strike rate greater than the avg. odds obtained ?
Must be psychics if they are ?

I'm sure there are plenty as with any sport

FINE AS FROG HAIR
24 Nov 11 22:56 Joined: 12 Mar 07 | Topic/replies: 4,302 | Blogger: FINE AS FROG HAIR's blog
A million bot operators ?
Really ?


No, which is my point.

tober
You would think and hope so tober.
But I have a feeling that " individual" sports like tennis, involving literally one-off face to face personal elimination confrontations all the time, prove to be more , or perhaps even too, difficult to forecast over time.
Also tennis results turn literally on one or two key in play moments, eg close line calls, key double faults, injury flareups etc etc, thus I wonder if you can only win if you are following each match very closely in play.
I dn't think team sports are quite as fickle or unpredictable.
For sure they have their key in play moments too, but not in quite the same critical influential manner as they occur seemingly more ften han not in tennis.

cat
Fair enough I get what you mean now.
But whilst on this point what would you think is the ratio of successful bot operators to unsuccessful ones ?
Much, much higher than in the manual operator arena I would suspect.

I doubt there are many unsuccessful bot operators.  Those who have devised a bot will have a more business like attitude towards losing money than recreational punters and obsessive wannabes and reach for the "off" button before too long.

Particular moments of luck, net cords etc are not important in compiling odds as they will be just as likely to happen for or against.

The main factor in calculating odds will be the abilty of the players in relation to each other, other things can be considered such as likely motivation, playing surface, recent injuries, H2H, it can all be factored in.

The Fact is though the market may be correct, on average , over the long term,at starting prices, it is still wrong for a huge proportion of the time it is open before the start.

Look at tonight's match, Ferrer v Berdych: [i]Berdych has been matched at all odds between 1.67 and 2.24[/i]!!  .Maybe he will go off at 2.08 and maybe the market will be right about that if so . But there is no way in the world that the market had been right the whole time since it opened ! What on earth can possibly have happened, in the 24 hrs before the match, to make all those different prices correct at any given moment? 

I don't know enough about Tennis to say what his true odds are , but people who do will surely have got matched at odds they consider value across that huge spread of odds.

If that is typical of how tennis goes pre match then it must be one of the easiest sports to win on pre match for those with good compiling skills.

All good stuff tober.
That pre-match odds variation on the Ferrer/Berdych match is huge.
I find it hard to believe that it would be the norm for the majority of matches over the year though.
It probably all boils down to being truly selective and patient for the occasional good betting opportunities to arise as in all sports.
But I still remain inherently wary and suspicious of the enormous performance inconsistencies in individual sports, due to unknown " personal " factors concering the players bodies and minds.

Cat
As a matter of general interest, do you feel you could now make money without the aid of a bot ?
Is your edge totally dependent on being able to bot up, or does the botting up just make it less painful/boring to apply ?

tobermory, I haven't followed tennis close lately so can't sau for sure, but I think the large fluctuation in the prices in that match is due to results in the other matches in that group which was played earlier. Those matches would have a great influence on who that would qualify depending on the result.

What happened with Ferrer Berdych is special, because this is a tournament with a round robin system, so the outcome of Tipsa Djoko this afternoon changed a bit the situation for Ferrer Berdych, in a way i don't have time to explain now.

To answer to your question, FAFH, many bettors on tennis seem mainly to trade in-play as the very quick movements of odds give you many possibilities, but i'm sure there must some punters with huge knowledge who can be successful with straight bets. I don't think i saw one of them on the forum though.
I really think there are an infinity of winning strategies, everybody have to find his way with his own skills and knowledge. I use myself 10-12 strategies, it depends the situation and the match.

ok guys, don't follow tennis myself, thought that was pretty extraordinary

Froggy, I used to make money manually and my bot is an automation of what I used to do.  I reaction I  could still do it that way although  the markets I used to play have changed a lot and I expect my edge would be much smaller now.

Those tennis odds are not extraordinary by any means. There have been various reasons for the price changing.

Yeah but not many scenarios are round robin ones like this one and so is it the norm ?

jimmy is right, the odds moved last night but not much this afternoon when tipsa djokovic was played. I never really bother with pre-match movements so i can't say if it's usual

The number of ir tennis odds compilers who were lying dormant in this country awaiting the birth of betfair strongly suggests an alien conspiracy to me. Maybe Warren Buffet's got a point and it's hard coded into Brit DNA.

Flies round sh1te imo.

I would say 80% of people on tennis forum are not english, i don't the proportion for the punters of course

It was a silly statement on my part abolo. As if aliens would discriminate with their DNA manipulatrion.

They could discriminate if Winston Churchill made a secret pact with them

LOL Feck, I like that, but the fact is flies around **** punters are here to stay and we'll see more and more of them IMO, so we just have to deal with it (or invest in some fly zapper) :)

If you want to earn a living from sports betting, you have to work very hard and long, fact. I did bet long time on football and think i knew more about it than some journalists. Maybe Betfair should force us to write pieces on our sport, at least we would be productive.

One of my journalist colleagues said he thought journalism was about knowing just enough to get away with it. There's a lot of truth to that.  If you're a journalist, the key is being able to construct interesting write-ups that contain one or two fascinating 'facts' that make the reader think you have strong knowledge of the industry. The actual success of your picks will be far less important than your ability to sound interesting and plausible.

Journalists are often hopping around doing lots of write-ups, and they generally lack the time needed to really crunch the figures.  And, of course, virtually nobody seeking a job in sports journalism will have to prove that they have a long and strong betting record in their chosen sport. All they'll really need to do is show that they know about the top trainers and jockeys, and that they can talk a little about great horses from times past. In-depth knowledge of betting techniques would, I suspect, be much further down the list of priorities.

Yes it's true, and they need to work very fast, so they need to stick to the essential.
I think sometimes about one thing. To trade on an event give me a deep feeling of what have been the scenario of the match, the crucial turning points, even more because my money was on the line and so i was personnally involved. With time you build love/hate feelings with the players because of the money they made you win or lose. I was not at all a tennis fan before i started to try to bet a little on it and became one through betting.

is Contrarian up for this? as i said, picking winners is probably not his style so your price of 4 on me winning is value. lump on boys

Yeah I agree with this. I dont know why I keep logging on here, but I think I'm trying to get that big win. My job pays minimum wage, and I can't find any other type of income other than this tripe. Betfair = Butt Rape.

a very interesting thread ..

but i am surprised to see that most of the pros on here are discounting "luck" blindly.

bad luck , negative variance , black swan whatever you call it is a possibility and i find it strange that most on here are dismissing it as something that does not affect them if they have Edge, discipline etc etc. i would have thought most pros would be very worried for such eventualities and would have built some safeguards.

i remember investor had a big loss when newcastle came back from 4 goals down to draw.. i also remember steptoes lost some huge amount when ireland won against england in this years cricket world cup..  trevh always quotes the heads at 2.2 analogy but what do you do if there are continuous 50 tails and your bank is finished.... what if there were many such continuous negative or "unlucky" results..

just because anyone has won for last 10 years does not mean that they will win the next 10.. edge helps you find the value bet but it is luck finally that decides whether you win or not.. there i have said it

Statistical probabilty dictates that almost all of any group of winning punters have just been lucky.


Utter nonsense, of course. Johnny has read something that sounds clever and explains his own lack of success and believes it is true in all cases. It aint FACT.

Well Ocean, I have the luxury of being able to temporarily give anything that generates very volatile returns if necessary.

When I am doing well, I scale up and accept a lot more variance. When things are going poorly, I focus on highly consistent strategies.

Placing straight bets, the smaller your edge is, the more important luck becomes. I would agree that luck virtually always plays a role for winners and losers alike.

When trading, the 'smaller your edge, the more important luck is' bit doesn't hold. For instance, someone running a bot that does cross market arbitrage, could theoretically make money every single day and yet pay 90% of GP in commission.

If you were straight backing evens shots at 2.2, Kelly staking would sort out any crazy runs you might have.

Coming back to straight betting and the idea of smaller edge = more reliant on luck (with level staking):
If you can bet 2.04 on 2.00 shots and place 10,000 bets, you can make x,-x or 4x depending on luck.
However, if you can bet 2.2 on 2.00 shots and place 10,000 bets, you will make x or .9x or 1.1x it will not vary that much.

There is a lack of precision in many of the statements which makes it pssible to argue against tem even though the essence of what the poster has said, the spirit if you like, may be true.

Statistical probabilty dictates that almost all of any group of winning punters have just been lucky.


What's missing from this statement is a) term  b)sample size c)av win %/av price d)trading strategy
and the phrase "almost all of any group" is unqualified and unverified. But the essence is that a % of winners are winners due to variance/luck alone. The proportion of all or of total won is unknown. The couple who won £100m plus on the Euro lottery would proobably not argue that luck is involved sometimes.

If you were straight backing evens shots at 2.2, Kelly staking would sort out any crazy runs you might have.


Depends on a) length of term b) proportion of Kelly used c) certainty of achieving 2.2 against 2.0 chance - how do you know? Kelyy staking may work on paper but in practice it has its "ups and downs" and could take a very long time to pay off if 5bank gets to

if bank drops to

if banks drops to less than 1% (problem with less than symbol)

ZZZZZZZZZZZZZZ

" Just my luck " is a phrase that applies to all gamblers, good or bad.
But in the case of good gamblers, it should be just a passing phase.
For bad gamblers , however, it could be terminal .
Sandown is right about Kelly staking though.
A run of " bad luck" can be severely detrimental to the short term mental health of even very good gamblers, if nothing else.

agree investor and FAFH, the good gamblers will have fall back strategies or systems that they can use when having a bad run... maybe the good old point about luck being equal to preparation is true

sandown, i am also not convinced by kelly but thats for another thread another day

My personal view is that persistent winners are able to consistently put themselves in positions where they maximise good luck and minimise bad luck, whereas others can't.

Just my view mind.

Ocean, I stake in such a way that 50 tails (as you say) would hardly dent the bank let alone finish it. I'm here for the long run. I've never bothered with 'famous' staking plans, and I've also said many times that I use simple level staking to 0.2% of the bank, raising or reducing stakes as the bank alters. I suppose some would see that as a kelly variant but it's my own method.

I also have my own weekly withdrawal method which ensures I get a 'smoothed' wage every Sunday (I believe a weekly reward is very important) roughly based on withdrawing half the amount above a certain point of the bank.

0.2%? Percentage backing is rubbish! It increases variance,loading all the profit into very unlikely scenarios.

Suppose you back 1000 coin tosses at fair odds.

Let us say you bet 0.2% each time.

If 500 are heads, 500 tails, then no matter which order heads and tails come out (thankfully, given the massive number of permutations), you would have your bank * (1.002^500) *0.998^500 =0.9980

So you need to do better than the expected number of wins to make a profit.

Basically you lose a lot of ev to the results that aren't going to happen.

Let's say you get 1000 heads (wins). Level staking with a bet size of 0.2% INITIAL bank for all bets, you'd end on 3 times your bank. With your plan, you'd win 1.002^1000=7.37 times bank.

Likewise, 250 heads or less puts the level staking into negative territory, while your staking plan never goes negative. But under 250/1000 is so unlikely (web chart says 1e-59), that again you are "spending" ev from the most likely outcomes.

Why do people always go on about coin tossing? That has absolutely nothing to do with sports betting whatsoever. The sooner people get that into their heads the better.

The sooner people get that into their tails the better

trevh always quotes the heads at 2.2 analogy but what do you do if there are continuous 50 tails and your bank is finished

Like asking what do you if a meteorite crashes through the ceiling and lands on your head.

Jimmy as it is an example of how you would win just by taking odds better than the probablity because the probablity is clear.

The true probablity is less clear in Sports Betting but it does exist.

If it doesn't then Federer vs No. 427 in the world would always be priced at Evens the pair.

Jimmy69: It's an easy way to show that with fair odds you can screw yourself with your own staking plan.

All sports are just random events, and a fair evens shot makes the maths simple, although if you want you can name your market and I'll do the stats with that market instead.

All analyses should be based on a fair market. If you can work out how to break even safely on a fair market, then you can be happy knowing your edge will take you into profit.

If your strategy has you losing money on a fair market most the time, then you need to examine your appetite for risk.

Nothing you can do while on a fair market can change your expectation, but what it can do is change your variance, and alter the outcomes in different scenarios.

That is why "coin tossing" is important. Next time I'll call it by their real name, "bernoulli trials"

xkcd.com/904/

Some people like to focus on the narrative, personally I prefer to focus on finding the weights. :)

I'm happy to let the mathematicians calculate their "true odds" and do their market making.  Give me a bit of working-knowledge any day.

Even as a mathematician the last thing I would ever do would be to try to calculate the true odds of a single sporting event, it cannot be done.

But understanding how to manage expectation (move EV around, for example by creating some nightmare but very unlikely scenarios you can put the EV from those onto the more likely outcomes to boost regular profit. This is what Lehman Brothers did )

ror
As you are apparently a learned mathematician ( welcome btw) please could you attemt to answer the following, if it is at all clear to you what I am saying.
What if one thinks one has found an edge by analysing a large bank of historical data.
This edge is a pure flat bet one  ( the only good type I believe).
Then one takes this large sample and randomly mixes it up ( say) in thousands of different permutations of timing sequences.
This enables a view then to be established on the max level of worts case drawdown of any bank ( in other words expected worst case losing runs).
Then one increases one's bet size (based on the ratio of this expected worst case drawdown amount to the current bank ) if and when the accumulated bank increases , but one never decreases the bet size ?

FINE AS A FROG HAIR
What if one thinks one has found an edge by analysing a large bank of historical data.
This edge is a pure flat bet one  ( the only good type I believe).
Then one takes this large sample and randomly mixes it up ( say) in thousands of different permutations of timing sequences.
This enables a view then to be established on the max level of worts case drawdown of any bank ( in other words expected worst case losing runs).


This is quite an inventive thing to do, and I think it would certainly help understand your appetite for risk. Do bear in mind though that the number of different arrangements (permutations in maths speak) will be very very large.

For instance, if you had even 10 different results, then unless some of those are the same (so the same odds and outcome) then the number of permutations is 10! which is over 3.6 million!

Another useful tool is to look at the "what if?" scenarios. In this one, instead of re-arranging orders, takes away 1 result from the pool.

So for instance if I had the following outcomes:

2
17
-5
-5
-13
5
10
-12
15
-2


Now overall you've made a +12 profit over the 10 results.

In this analysis you would "take away" one result from the pool. This has the advantage that for 10 results, only 10 sums are needed.

Basically it shows what your profit would have been if not for each result. This in part shows how robust (using this in a non-mathematical sense as I think it means something specific in maths but I don't remember what!) it is. If missing just one result puts your profit into loss, you might wonder if it's really a profitable system. Really a winning system should be robust enough to withstand removing your best couple of results.

So in this case it would be:

2	10
17	-5
-5	17
-5	17
-13	25
5	7
10	2
-12	24
15	-3
-2	14

So 20% of the time, if you missed one result you'd have made a loss. Also 20% of the time you might have made twice the profit!

Another useful thing to do (especially for larger datasets) is instead of discarding one result at a time, if you discard both your top 10% and your worst 10% results, and analyse the middle 80% only.

This will depend on your strategy, if you're a long odds backer then doing that might wipe out all your profit!

But in those cases you could say "wipe out your best/worst 10% of days" rather than individual results.


FAFH:
Then one increases one's bet size (based on the ratio of this expected worst case drawdown amount to the current bank ) if and when the accumulated bank increases , but one never decreases the bet size ?

Never ever do this.

I cannot stress this enough. Modifying bet size based on percentage bank is bad enough, but increasing it as a percentage and then not decreasing is in the very definition of Gambler's Ruin.

From Teh Wiki:

The original meaning is that a gambler who raises his bet to a fixed fraction of bankroll when he wins, but does not reduce it when he loses, will eventually go broke, even if he has a positive expected value on each bet.


So please, never do this. I'm not sure what you meant by "ratio of this expected worst case drawdown".

If you're comfortable level staking then I would stick to that, it has lots of good things going for it.

I notice I forgot to explain that 10! is 10 factorial, which is 10x9x8x7x6x5x4x3x2x1.

So instead of 10 we use n.

n! (n factorial) increases very, very fast. Faster than exponential .

Here is n! for 0 to 10.

0	1
1	1
2	2
3	6
4	24
5	120
6	720
7	5040
8	40320
9	362880
10	3628800

Unfortunately BF doesn't have a spoiler tag but this is 100!
I've broken it down in 12 digit chunks so I don't break phones viewing this, but this is all one number!

933262154439
441526816992
388562667004
907159682643
816214685929
638952175999
932299156089
414639761565
182862536979
208272237582
511852109168
640000000000
000000000000
00

Dodging doing anything a factorial number of times is very important in the kind of stuff I do for a living.

So when I ask should you increase your flat bet size ?.
You can't stay forever at your original starting bet size, not if you expect to make reasonably good earnings. ( That is assuming you don't start on day one with a very, very large bank and an accordingly very, very large flat bet size.
Also on the gamblers ruin matter.
I fail to see that if you establish that a worst case drawdown situation is ( say) 100 units for example, then if your bet size is set at ( say) 5 times this, that is a at a ratio of 1/500 of your bank at its last peak, then unless you experience a drawdown of more than 5 times your forecasted expected worst case scenario ( that is a real black swan scenario), before you get back into profit again, then how can you be wiped out ?

Any given length of losses will happen eventually*.


*If we say n is the number of bets made, then the probability of going bust as n tends to infinity equals 1.

OK, so it's very very unlikely to actually happen to you, but if you are only betting 1/500th of your bank, then unless you are backing long odds (in which case 500 losses might not be that unlikely) you'll unlikely make better money than you'd make in the bank!

There really isn't an "expected worst case". I'm sorry if I find this hard to explain, it's because "expectation" is a mathematical term (although one I do abuse in other threads).

Basically you could pick a probability and say "OK I want a system that means I won't lose my bank in 998/1000 cases", and your system would certainly pass that.

But that's not the only problem with "increase and never decrease" systems, it means you're always pushing yourself away from your comfort zone and are always maximally discomfort during any losing streak! This will lead to frustration.

For instance if you're evens betting, then if you are at a current new maximum bank, then winning 3 then losing 3 will mean you end up down.

As I think I said either upthread or on another thread, backing a percentage of your bank also moves a lot of your expected winnings onto fantasy results that are less likely than euromillions!

But the addition of not decreasing your bet size just further means you might end up with your current bank in a year's time, but now you're betting larger stakes. Would you be comfortable with that?

You should pick a stake size you're comfortable using and then just use that. You still risk being wiped out (by the finite vs infinite bank, you can't avoid this one), but at least you'll be comfortable during the down swings which might make them easier to get out of.

Also level staking means it is easier to compare results month to month which is important for checking you're really making money.

What would I do? I'd level stake, then every month my bank is up I'd withdraw the money. Now your bank is the right size for your stake again!

If you don't withdraw then you're not winning money! This is what people miss when they are running good they just up their bets and get back to average. They might have a buzz and feel good while they're up but if they never withdrew the money they've not won squat!

Of course I would also therefore recommend that any month you're down you top up your bank to the right size for your stake. This might feel difficult but the in/out from your bank statement helps you keep yourself honest about if you're a winning or losing gambler!

All sports are not just random events. What about the fixed matches which happen every week...how does your maths work those out

Trevh why do you never post in "how much has everyone won" thread?

ror :  0.2%? Percentage backing is rubbish! It increases variance,loading all the profit into very unlikely scenarios.

Basically you lose a lot of ev to the results that aren't going to happen.

As I don't know the outcome of any results I keep my stake the same on all. Perhaps what I said before came across wrong, in that I don't adjust bet size during the week's betting, and I don't adjust bet size upwards (I used to) after a profitable week because I'm currently happy sustaining this level, but I do reduce stake size to 0.2% of a new lowered bank if it's been a losing week. This works very well for me and it's not something I would change, the stake size never alters very much at all.

ror : What would I do? I'd level stake, then every month my bank is up I'd withdraw the money. Now your bank is the right size for your stake again!

Of course I would also therefore recommend that any month you're down you top up your bank to the right size for your stake.

The first bit is roughly what I do, only I withdraw every week not month so my bank remains pretty constant as does my stake. I never top up funds after a losing week though, I like to build back the loss using a slightly smaller stake (0.2% of lowered bank) as that gives me the mental security of riding out potentially bad runs. Plus the fact that in Aug 09 I said that if I ever had to deposit again I would give up gambling, and meant it.

I agree with you Frog that to build a bank up to the size you're happy with to operate level stakes, you obviously need to increase the stake size accordingly thus also decrease accordingly as ror said, although he doesn't like that method. As we're all aware though, there's more to getting it right than best theory dictates, I mean we need to do what we're most comfortable with to create security because we're not robots.

Frimpong, if that's the thread on the footy forum, I don't think I'll bother :) I did say once before that I'd post on a general betting thread though.

Btw ror, you said "what would I do?" Are you just a theorist then?

Sorry ror but I'm afraid that I do not find your reasoning convincing.
Btw I'm not talking about consecutive losses or anything like that. I'm talking about extended downturns made up of both many wins and losses.
If you can estimate what such downturns are likely to be, obviously not to 100% certainty but to a strong degree of certainty based on extensive testing of back data, then that downturn figure should be the basis for the percentage of your bank you ever put on one bet.
It would make no sense then to decrease your bet size if you are experiencing losses which are well within your expected " bad run " parameters.
If you don't believe the losses will turn around then you shouldn't be just decreasing your bet sises, you should in fact not be betting any more at all, as you would effectively be just putting in good money after bad.
You have to believe that your basic "edge" is still there even when experiencing bad runs. Otherwise what's the point of discovering and trying to exploit any edge ?
If you want to use a very simplistic analogy, you could say that those investors who increase their positions in the stock mkt. when a particular share price goes down are exhibiting the same confidemce in their "edge", by increasing rather than decreasing their exposure to that particular share in adverse mkt. conditions. They do not cut and run at the first sign of any losses.

Trevh
Our posts sort of crossed.
I like the sound of what you do, except for the decreasing of stakes if and when a bad run occurs.
I believe that is not correct, for the reasons I have just outlined.
Vive la difference.

Frog : I fail to see that if you establish that a worst case drawdown situation is ( say) 100 units for example, then if your bet size is set at ( say) 5 times this, that is a at a ratio of 1/500 of your bank at its last peak, then unless you experience a drawdown of more than 5 times your forecasted expected worst case scenario ( that is a real black swan scenario), before you get back into profit again, then how can you be wiped out ?

Misunderstood you above Frog, I know what you mean though, but I had a draw-down earlier in the year which was more than anything I'd previously experienced, and if I'd carried on at the same level of staking it would have come close to wiping the bank, and that's using just 0.2% stakes. As it happens I reduced accordingly and recovered to full bank within 2 weeks - no panic. I wouldn't want to be in that situation using full stakes with no reduction.

Clearly the black swan I was talking about.
Without doubt they are swimming around and you have to be constantly on the alert.
But overreacting is probably as bad as underreacting, though I would agree that overreaction is less likely to ever result in a total wipe out.
But this is a risk game, as there can never really be a no-risk scenario that is highly profitable ( unless you are one of those fortunate few with those fiendishly clever in-running bots).

Yep, we all should do what suits us best obviously, and reducing stakes suits me fine. Another part of gambling - learning your strengths and weaknesses. Like I said above, I don't think best theory is always best practice "(unless you are one of those fortunate few with those fiendishly clever in-running bots)". :)

Ah ok trevh, I think i misunderstood you to be using a strict bank % as many on here do (and recommend) to their peril.

In fact not increasing but sometimes decreasing your bet size may well be a more stable strategy. You would eventually cease betting (if taken literally, that your bet size could only decrease!) but it is clear you increase back to a level stakes cap.

I quite like that, it avoids discomfort or loading too much money into the unrealistic dream outcomes.

I'm actually going to white a program to show some outcomes under different staking plans. There is a dangerous (very high risk) staking plan that involves actually betting  more when your bank is down and less while your bank is up but it has a high bust probability. If you don't go bust you make nice returns though.

P.s Yes I think it is fair to say I spend more time on theory than betting. This is mostly because I don't touch horses, so there is very little sport right now! Also I work, so have time to think about this stuff when I can't actually bet.

I tend to minimum bet most the time. While I could stake higher, I get as much pleasure out of making a £2 profit as a £20 one. I'm not here to make money, I'm here to increase my sporting (and xfactor) knowledge and interest.

The mathematics of gambling and the psychology of gamblers I find fascinating. I don't work in the city but if it is anything like this place I would hate it. I've made it my mission to tackle some of the myths doing the rounds.

Good on you Ror...but you do seem to be making gambling a little more complicated than it actually is

I gave up on this thread when i read 'all sports are just random events'. Only a number-crunching addled mathematician could come out with that and this forum seems to be full of them. Clearly not got the first clue about sport.

I reacted to that comment too DI......Typed out a start of a response.....then decided not to bother.

ror has stated that he/she does not bet on HORSE RACING......explains a lot!

ror......RETIREMENT STAKING PLAN.....should be one you test...and KELLY. GL

Thanks for the suggestion.

Any other staking recommendations?

LEVEL STAKING does not exploit any "edge" you might have.........I suspect many who believe they have an edge re FOOTBALL betting use that "method".

So do not recommend that !

DFCIRONMAN: Hopefully this analysis should show some plans which are better than level stakes.

If I do it properly I might even be able to release it as a general tool for others to run their own analysis with.

ror, I presume you'll be including some Kelly or Optimal f staking in the simulations?

I'll try to include any I'm asked to include.

Kelly I can include where I build in an edge, but without an edge Kelly can't really work.

If you'd like me to include a staking plan please link to a decent description so I can check we're discussing the same thing!

Kelly will do fine. And it should work just fine without an edge, it'll just tell you to bet 0% which will keep your bank at its highest possible level.

http://www.grandstand.com.au/retirementstakingplan/

http://www.professional-racing-tips.com/StakingPlanPages/Retirement.aspx


Plenty PLANS there!

Thanks guys :)

I've built the results engine, I've not yet worked into it the staking engines. I think that'll be the fun part.

But currently you can pick any number of runners and assign a probability to each. It'll then run that race a thousand times, look at what happens to your bank (essentially a random walk), dump those stats out, then repeat that whole process thousands of times.

(If anyone is interested, the pseudo-random number generator I'll be using is mersenne twister. It's incredibly good for monte carlo as not only is it unbiased but it's LIGHTNING fast.)

How are you initialising your Mersenne twister?

Initially time(0) but might use /dev/urandom or just "What seed would you like to use?" works well for monte carlo so you can repeat runs to check for interesting stuff after the fact.

I should add: As long as all the repeated runs etc are processed inside the programme, then having a weak seed isn't a problem at all, and on the same architecture (I think?) letting people input seeds lets you 'share' results easily with others using the same problem. (I could be wrong about this last point?)

I think that it is possible to choose "poor" seeds for the Mersenne twister, that is ones which will give you autocorrelated variates, but if you try the results with a few different approaches it should be apparent if some of them are odd.

Once you have your engine up and running it would be interesting to build a population of random bettors and see how quickly the wealth moves towards a small subset of the population (which it almost certianly will). The test for a market containing experts would be if the wealth moves to a concentrated few in a faster manner than your simulation.

Sadly, only Betfair would have the real-life data but we might be able to get enough info from them to compare to the simulation.

Two quants exchanging ideas.
Well there goes the neigbourhood.