The Importance Of Value

[Betulator]

Hi Folks, I'm relatively new here, so hello y'all. I wanted to go into my research on value betting and why it's so important, many of the experienced punters on the forum will know all about value, so this is aimed at people who don't, in a bid to assist you to bet better lol.

The concept of value odds is relatively simple, a bookmaker offers odds, in the odds is a margin for the bookmaker, so to determine what is value we have to go through a few steps, which i will do my best to explain.

On Football Systems... there is no bad football system, only poor value, any system can be profitable if value is achieved, the only difference from one system to another is the variance, for example a system based on homes may have a strike rate of 50% so you lose 1 in 2, a correct score system may have a strike rate of 10% so you lose 1 in 10, both will be profitable if value is achieved. It's really just a question of your personal tolerance to variance, if you hate long losing streaks, go for something that wins often, if you have the patience of Job, fine go for a high variance.

The first step in determining value is working out what the bookmakers margin is:-
Formula : 1/Home Odds + 1/ Draw Odds + 1/Away Odds, once you have this number subtract 1 then multiply by 100 for a %

Ok so now we know what the bookies margin is, we can move onto the next step, which is calculating the true odds for the game

There are 4 methods for doing this

Even Margin -EM where the margin is applied to the odds evenly across all 3 outcomes
Margin Proportional to Odds MPTO where the margin is applied proportional to the odds or share of the book
there are 2 more Odds Ratio and Logarithmic Function both of which give results so close to MPTO that Im not going to discuss them as they are both complex in their maths.

Even margin is a poor method, the favourite tends to have odds too high, that leaves us with MPTO, which having used it for years is probably the best method

to calculate MPTO odds =(3*Home Odds)/(3-(Margin*Home Odds)) do the same for Draw and Away, you should now have true odds.

To compensate for Betfair commission take these true odds and on the profit ie odds of 1.50 the profit is 0.50 multiply the profit by .02045 and add that to the true odds calculated. You now have the value odds including betfair commission for each outcome...

Place above this value and you will win over the long term, place below and you will lose, assuming you dont have an edge with your selection itself.

Hope this has been some help to someone Cheers

 

[JennyK]

Hi Betulator,

I would like to offer a different viewpoint.

"True" (and truth) are difficult concepts and to my mind Richard Rorty got it right when he preferred the notion of warranted (ie warranted on the evidence). From this perspective one can comfortably say that something is warranted but may not be true, and in real life, including racing, that happens a lot.

Perhaps nowhere is the confusion between true and warranted greater than in relation to backing horses. Before a race there will almost always be a variety of opinions as to the likely outcome, of which a bookmaker's price is just one. To imagine that any amount of adjusting the bookmaker's prices creates something that can properly be called "true" odds from which one can identify "value" is a fallacy.

What we have before a race are opinions, and anyone who backs horses seriously will know that with experience she or he has a sense of relative strength. Occasionally one thinks one has identifed what might be referred to as a racing certainly (ie a horse very likely to win) while on others one which has a clear chance but is far from a racing certainty. When one has a sense of the field and the relative strength one judges the one (or more) one is thinking of backing, one can make a further judgement about "value". And indeed Mick's post about his selection High Security for the 8.10 at Ayr this evening on one of the VDW threads is exactly how, in my opinion, any rational backer proceeds. Weighing its chance on the criteria one uses, one takes a view about the price warranted by that weighing up. That price is in no statistical sense the "true" odds of that horse winning, and may bear no relationship to the odds bookmakers offer. it is no more, but no less, than the price one feels is the minimum one would acccept for hazarding one's stake. On exactly the same horse in the same race, others will have reached different views, perhaps thinking the price the bookmaker or the Betfair market is offering is generous or too short, depending on their weighing up of the evidence.

After the race we move from the period of opinions and our often very different assessments of the then available evidence (and our view about the odds warranted by that evidence) to that of fact - X has won and all the others have lost. Then we can be said to have true odds - winner 100%, all the rest 0% - but that is of no practical consequence. Making money by backing horses to win comes down to the ability to judge likelihood of winning and then judge the price one will accept for the risk one will be wrong. Those with good judgement make money, others don't.

 

[PHS]

 

[gerry]

I will try give my take on it and use a actual race to see what happens and i have decided to go for the 4 20 haydock the first thing i notice is its 3yo race with very light racing this season so i am already worried about form in it.
But since i study all the horses form from fav down as thats the way they are in betting , i am already thinking 4/1 the field is not bad could be value here. The first horse ARARAT was run in decent race first time out after not bad performances as 2yo stayed on nicely in to fifth but good performance. And now dropped three classes back down to what could have been a realistic race in the first place so i was really surprised to find horse with that kind of form in this.
Then i went down the rest who had slightly similar form to his 2yo form but then started out this year with similar form and didnt look like they had improved anything special and certainly none has raced in class of ararat this year.

So now i have ararat as a possible bet but as i only looked at race today it looks like i possible have lost the 6/1 available earlier or last night and is currently 4/1.
So although i have horse i like is it value as this is what this is about here, well the truth is i dont know what i do know is when i looked at this race before even studying anything i seen 4/1 fav so i am thinking oh might find a nice price around 8/1 or 10/1 but i cant as i cant justify anything other than arafat.
So then i look at why 4/1 well i can see why its being lowered as form stands out a little but there could be improversa nd also is it deff going to run to first time out form again.
I do know in breeding it should love the 7fur but hood shows there some thing that bothers them, Is tom marquand on it a good thingor bad i am not sure as unusual booking for trainer.
To run well at wolver and yarmouth then newmarket tells me the horse is versatile and not to many problemsa lthough run stinker when fav at redcar but got unbalanced there after getting tightned up so thats possible forgetable so there seems exscuses yet all in all consistant horse so far.
So i seem to find exscuses for it and it is on my eyes in a race it can win so what price do i value it at as when every one said find value all or finds are differant and or value is differant so i am looking at this and honestly typing this down has helped as i still didnt know what i valued it at.
But now i am more clearer than ever about its chances and value yet i could be totally wrong as only after race will i see if my calculations were even close on the day.
Most of my fancies do seem to get cut after i have picked them just obviously my system must be to logical and similar to the majority.
Anyway i would personnally think the 6/1 was a value bet, the 4/1 and you have to for minute forget it once was 6/1 is it possible still value i think possibly not.
So should you leave it alone now or still bet it because you found it to late or is the sway of money for it a other indiction you where right to find it in first place.
I would say pitty i didnt study it last night and will wait with interest how it runs today.

 

[Betulator]

Hi Betulator,

I would like to offer a different viewpoint.

"True" (and truth) are difficult concepts and to my mind Richard Rorty got it right when he preferred the notion of warranted (ie warranted on the evidence). From this perspective one can comfortably say that something is warranted but may not be true, and in real life, including racing, that happens a lot.

Perhaps nowhere is the confusion between true and warranted greater than in relation to backing horses. Before a race there will almost always be a variety of opinions as to the likely outcome, of which a bookmaker's price is just one. To imagine that any amount of adjusting the bookmaker's prices creates something that can properly be called "true" odds from which one can identify "value" is a fallacy.

What we have before a race are opinions, and anyone who backs horses seriously will know that with experience she or he has a sense of relative strength. Occasionally one thinks one has identifed what might be referred to as a racing certainly (ie a horse very likely to win) while on others one which has a clear chance but is far from a racing certainty. When one has a sense of the field and the relative strength one judges the one (or more) one is thinking of backing, one can make a further judgement about "value". And indeed Mick's post about his selection High Security for the 8.10 at Ayr this evening on one of the VDW threads is exactly how, in my opinion, any rational backer proceeds. Weighing its chance on the criteria one uses, one takes a view about the price warranted by that weighing up. That price is in no statistical sense the "true" odds of that horse winning, and may bear no relationship to the odds bookmakers offer. it is no more, but no less, than the price one feels is the minimum one would acccept for hazarding one's stake. On exactly the same horse in the same race, others will have reached different views, perhaps thinking the price the bookmaker or the Betfair market is offering is generous or too short, depending on their weighing up of the evidence.

After the race we move from the period of opinions and our often very different assessments of the then available evidence (and our view about the odds warranted by that evidence) to that of fact - X has won and all the others have lost. Then we can be said to have true odds - winner 100%, all the rest 0% - but that is of no practical consequence. Making money by backing horses to win comes down to the ability to judge likelihood of winning and then judge the price one will accept for the risk one will be wrong. Those with good judgement make money, others don't.

Ok, I understand your POV but when you consider "True" or fair odds you are not considering just one game, you are considering hundreds or thousands of games, if i work out the true probability based on the sharpest bookmaker (Pinnacle) and it is say 80%, that does not mean that the team is 80% likely to win the match, if you consider after the game, the team won did that mean it was 100%, if it drew or lost, was that part of the 20%... it's not valid on one game. It is valid however on an average over 1000 games or 20000. Pinnacle true probability (and hence true odds) for 23000 games over 37 leagues, the actual results over this sample, reality Home 43.6% Draw 26.4% Away 30%. Pinnacles calculated true probability for the same sample is Home 43.5% Draw 26.1% Away 30.4%. !!!! that's accurate, if i then select any of those outcomes and place a bet on every one above the true odds calculated, I'll make money.
The other point you make is relating to the opinion of crowds, here's a fun trick I'll use as an example, if you have a competition where there is a giant jar full of small sweets and the competition is to guess the number of sweets in a jar, if one person guesses, they are unlikely to get it right but lets say 20000 people all have a guess, if you add up the guesses for all 20000 people and then divide by 20000 to get an average guess, you will almost always be within 1 or 2 sweets of the total... The wisdom of crowds in football is exactly the same except the guesses are money. The money flow is a very good way of determining the match outcome, and the more money the better. It's very accurate over the long run.

 

[Betulator]

I will try give my take on it and use a actual race to see what happens and i have decided to go for the 4 20 haydock the first thing i notice is its 3yo race with very light racing this season so i am already worried about form in it.
But since i study all the horses form from fav down as thats the way they are in betting , i am already thinking 4/1 the field is not bad could be value here. The first horse ARARAT was run in decent race first time out after not bad performances as 2yo stayed on nicely in to fifth but good performance. And now dropped three classes back down to what could have been a realistic race in the first place so i was really surprised to find horse with that kind of form in this.
Then i went down the rest who had slightly similar form to his 2yo form but then started out this year with similar form and didnt look like they had improved anything special and certainly none has raced in class of ararat this year.

So now i have ararat as a possible bet but as i only looked at race today it looks like i possible have lost the 6/1 available earlier or last night and is currently 4/1.
So although i have horse i like is it value as this is what this is about here, well the truth is i dont know what i do know is when i looked at this race before even studying anything i seen 4/1 fav so i am thinking oh might find a nice price around 8/1 or 10/1 but i cant as i cant justify anything other than arafat.
So then i look at why 4/1 well i can see why its being lowered as form stands out a little but there could be improversa nd also is it deff going to run to first time out form again.
I do know in breeding it should love the 7fur but hood shows there some thing that bothers them, Is tom marquand on it a good thingor bad i am not sure as unusual booking for trainer.
To run well at wolver and yarmouth then newmarket tells me the horse is versatile and not to many problemsa lthough run stinker when fav at redcar but got unbalanced there after getting tightned up so thats possible forgetable so there seems exscuses yet all in all consistant horse so far.
So i seem to find exscuses for it and it is on my eyes in a race it can win so what price do i value it at as when every one said find value all or finds are differant and or value is differant so i am looking at this and honestly typing this down has helped as i still didnt know what i valued it at.
But now i am more clearer than ever about its chances and value yet i could be totally wrong as only after race will i see if my calculations were even close on the day.
Most of my fancies do seem to get cut after i have picked them just obviously my system must be to logical and similar to the majority.
Anyway i would personnally think the 6/1 was a value bet, the 4/1 and you have to for minute forget it once was 6/1 is it possible still value i think possibly not.
So should you leave it alone now or still bet it because you found it to late or is the sway of money for it a other indiction you where right to find it in first place.
I would say pitty i didnt study it last night and will wait with interest how it runs today.

the problem with horse racing is the odds move fast, football things are a bit slower but i suggest looking at the odds the day before the race and having a good sample of races say 10000 in a historical, this means you're looking at the odds before the money starts, log the odds for each race 1 day before, then log the results.. this will give you both the expected % from the true odds and the reality, this would allow you to have a consistent baseline, i dont do horses but the principal is the same on the math

 

[JennyK]

"The wisdom of crowds in football is exactly the same except the guesses are money. The money flow is a very good way of determining the match outcome,"

I know nothing much about football or betting on it, but in horse racing, which with many more possible outcomes is clearly much more complex, the notion of the "wisdom of crowds" is a two-edged one. Yes, the selection of the majority, at least in terms of volume of money, ie the favourite, is statistically the most likely horse to win, with a much greater frequency over a large number of races, than say the sixth in the betting. But, roughly speaking, over that large number of races only a third of favourites win, so the "wisdom of crowds" is pretty pathetic.

And the idea of "crowds" in betting is an odd one. We bet as individuals, not as a crowd, and decision-taking is individual. Some may simply bet the nap of their favourite newspaper tipster, or pick a couple out from the racing page of the Sun during their lunch break. Others put serious time and effort into race analysis. On any single occasion the most casual punter may strike lucky - perhaps even attracted by the horse's name who goes on to win at huge odds. But those who know what they are doing and have developed good judgement through experience are, I suggest, more likely to get it right more often and show a profit long term.

As regards odds, I expect we have all had Gerry's experience and found we have missed what were better odds. Similarly, I have not infrequently taken a price on Betfair in the evening and when I go to the site a few minutes before the race the following day to watch it, find the price is considerably higher. One can allow oneself to be irritated by either, but actually they are neither here nor there. What matters to those who know what they are doing is their individual judgement on what I think of as the warranted price for the horse; the minimum price they will accept given their judgement of the likelihood of it losing. If, when one has that price in one's head and goes on to Betfair or a bookmaker's site, and finds the horse is available at a few points higher, that's just a bonus. It is what Mick reports about his experince with High Security yesterday that takes professionalism. Having made one's judgement about the lowest price one is prepared to take, NOT filling the bet when that is not available. There are no "true" odds or science in setting that price; simply the individual's judgement which, if good, will put her or him well ahead of the "wisdom of crowds".

 

[mick]

The description Value Odds lends itself to multiple interpretations and over time we each find our own best use. Mine took many years to craft but i am now comfortable with its application and this counts for plenty. The vast majority of my bets come as a result of identifying just one horse i feel interested in backing in a race.

When this occurs rather than attempt a whole race tissue I then create what i call a MAP Minimum Acceptable Price for my possible. Of course this will include considered dangers from the opposition and the negative aspects in my picks form, and there are always some of these. I guess more an art than a science but i prefer to think of it as hard earned experience.

Anyway once i have my MAP i will only bet if i can obtain this or better. I can certainly appreciate that this MO would not suit other punters but on balance it has worked well for myself. Speaking personally the only thing which hurts more than backing a loser is doing so at a perceived poor value price and i never suffer this.

While its a bold statement to make i would suggest that any backer who produces a long term profit will have been obtaining value as part of.

 

[ARAZI91]

Hi Folks, I'm relatively new here, so hello y'all. I wanted to go into my research on value betting and why it's so important, many of the experienced punters on the forum will know all about value, so this is aimed at people who don't, in a bid to assist you to bet better lol.

The concept of value odds is relatively simple, a bookmaker offers odds, in the odds is a margin for the bookmaker, so to determine what is value we have to go through a few steps, which i will do my best to explain.

On Football Systems... there is no bad football system, only poor value, any system can be profitable if value is achieved, the only difference from one system to another is the variance, for example a system based on homes may have a strike rate of 50% so you lose 1 in 2, a correct score system may have a strike rate of 10% so you lose 1 in 10, both will be profitable if value is achieved. It's really just a question of your personal tolerance to variance, if you hate long losing streaks, go for something that wins often, if you have the patience of Job, fine go for a high variance.

The first step in determining value is working out what the bookmakers margin is:-
Formula : 1/Home Odds + 1/ Draw Odds + 1/Away Odds, once you have this number subtract 1 then multiply by 100 for a %

Ok so now we know what the bookies margin is, we can move onto the next step, which is calculating the true odds for the game

There are 4 methods for doing this

Even Margin -EM where the margin is applied to the odds evenly across all 3 outcomes
Margin Proportional to Odds MPTO where the margin is applied proportional to the odds or share of the book
there are 2 more Odds Ratio and Logarithmic Function both of which give results so close to MPTO that Im not going to discuss them as they are both complex in their maths.

Even margin is a poor method, the favourite tends to have odds too high, that leaves us with MPTO, which having used it for years is probably the best method

to calculate MPTO odds =(3*Home Odds)/(3-(Margin*Home Odds)) do the same for Draw and Away, you should now have true odds.

To compensate for Betfair commission take these true odds and on the profit ie odds of 1.50 the profit is 0.50 multiply the profit by .02045 and add that to the true odds calculated. You now have the value odds including betfair commission for each outcome...

Place above this value and you will win over the long term, place below and you will lose, assuming you dont have an edge with your selection itself.

Hope this has been some help to someone Cheers

Interesting post but football is not my bag, horse racing is but "advantage gambling" follows the same principles no matter what the game is - all your doing here is removing the bookmakers overround/margin from games which Joseph Buchdahl covers so well in his books - where are the models, metrics and analytics that derive truly "true odds" and where is the process to "update" true odds using "new information" in a Bayesian sense where the word "new" is relative which is vital when the markets are so efficient these days. Here Joe talks about using "The Wisdom of the Crowds" to obtain an advantage in football betting.
https://www.football-data.co.uk/The_Wisdom_of_the_Crowd_updated.pdf

 

[JennyK]

" [The word ‘true’ used in this context is placed in inverted commas to denote that we don’t (nor can’t) know the true probability of a result a
priori, because sports, unlike casino games, are not the product of simple probabilistic functions. Rather, they can only be proved empirically a posteriori by analysing samples of results retrospectively.]"

Mr Buchdahl is spot on. Sadly, I've yet to find Betfair offering me the opportunity to bet a posteriori.

 

[mick]

Mr Buchdahl is spot on. Sadly, I've yet to find Betfair offering me the opportunity to bet a posteriori.

But they will give you a kick up the posteriori via there Premium Charge.!

 

[gerry]

I will try give my take on it and use a actual race to see what happens and i have decided to go for the 4 20 haydock the first thing i notice is its 3yo race with very light racing this season so i am already worried about form in it.
But since i study all the horses form from fav down as thats the way they are in betting , i am already thinking 4/1 the field is not bad could be value here. The first horse ARARAT was run in decent race first time out after not bad performances as 2yo stayed on nicely in to fifth but good performance. And now dropped three classes back down to what could have been a realistic race in the first place so i was really surprised to find horse with that kind of form in this.
Then i went down the rest who had slightly similar form to his 2yo form but then started out this year with similar form and didnt look like they had improved anything special and certainly none has raced in class of ararat this year.

So now i have ararat as a possible bet but as i only looked at race today it looks like i possible have lost the 6/1 available earlier or last night and is currently 4/1.
So although i have horse i like is it value as this is what this is about here, well the truth is i dont know what i do know is when i looked at this race before even studying anything i seen 4/1 fav so i am thinking oh might find a nice price around 8/1 or 10/1 but i cant as i cant justify anything other than arafat.
So then i look at why 4/1 well i can see why its being lowered as form stands out a little but there could be improversa nd also is it deff going to run to first time out form again.
I do know in breeding it should love the 7fur but hood shows there some thing that bothers them, Is tom marquand on it a good thingor bad i am not sure as unusual booking for trainer.
To run well at wolver and yarmouth then newmarket tells me the horse is versatile and not to many problemsa lthough run stinker when fav at redcar but got unbalanced there after getting tightned up so thats possible forgetable so there seems exscuses yet all in all consistant horse so far.
So i seem to find exscuses for it and it is on my eyes in a race it can win so what price do i value it at as when every one said find value all or finds are differant and or value is differant so i am looking at this and honestly typing this down has helped as i still didnt know what i valued it at.
But now i am more clearer than ever about its chances and value yet i could be totally wrong as only after race will i see if my calculations were even close on the day.
Most of my fancies do seem to get cut after i have picked them just obviously my system must be to logical and similar to the majority.
Anyway i would personnally think the 6/1 was a value bet, the 4/1 and you have to for minute forget it once was 6/1 is it possible still value i think possibly not.
So should you leave it alone now or still bet it because you found it to late or is the sway of money for it a other indiction you where right to find it in first place.
I would say pitty i didnt study it last night and will wait with interest how it runs today.

Well analysing the race now ARARAT finished 5th beaten 4 lengths after getting bet in to 0/30 fav so more money came for him which didnt help his cause so now we know in this perticular horse the sway of money made no differance bar the crowd thought it had good chance.
So the 6/1 you could still argue was value infact the 4/1 you could even argue was still value but the first reaction before even looking at race proved correct 3yo race with little this year form, so was all sorts of possible improvers from 2yo to 3yo.So i know its only one race

So i know its only one race but i could argue the race although there was hidden value bets just like the 6/1 ararat there was actually no value in this race and should have been left alone.
So i am saying the race was no value before looking but once you look you might find a value bet but what your doing is ignoring all the things you have gathered over years to access certain races.
And the reason i picked that race believe it or not was just for this trial, as i have for the first time possibly ever for last three days not found one race i thought was a bet race as they all were poor horses running against poor horses where i could not find one who had what i look for in bets.

So to finish of what i tried i found a value bet in a none value bet race which ended in defeat because there was to many ifs and buts about the other horses in the race.

 

[hedgehog]

My opinion doesn't count for much but value is a statistical concept and if you make a profit in the long run you are getting value with most of your bets. On a single race or match you can only make an informed decision about the horse or teams chance and hope. There's an old saying in America - 'You can't beat a race but you can beat the races'

Good luck and stay well

 

[ARAZI91]

Here's an example - Using a football match - Betfair are betting to a virtual 100% margin with the following
Team A win odds - 1.55
Draw - 4.54
Team B win odds - 7.34
Total book price (excluding commission for simplicity) 100.167%

You look at the bookmaker prices and decide to use the Logarithmic function to derive the "true odds"
The bookmakers are betting
Team A win odds - 1.45
Draw - 4.34
Team B win odds - 6.29

Using the Logarithmic function the "true odds" are
Team A win odds - 1.50
Draw - 5.00
Team B win odds - 7.50

But you have been modelling this league and have many inputs including xG, Per minutes played metrics for players in shots, assists, etc (Per 90s are better than per game metrics) ,Total shot ratios, passing accuracy in the opponents half, Key Pass metric ,The Big Chance metric ,strikers who are the most wasteful with chances and numerous other metrics. In the end you have a final number for the model that can be normalised against the strength of the opposition.
You want to know the probabilities of your model in this game and combine them logistically and exponentially with the "true odds"calculated earlier from the bookmakers odds with the vig/overround removed where we used the logarithmic function.
Primarily you want to calculate your models probabilities first then combine them logistically/exponentially with the true odds and then compare them with the Betfair market to see if their is "true " value there along with significance
Here's your models final numbers which go Team A - 1230.35 , the Draw - 580.95 and Team B - 434.86
Like this

Note there is a game/team confidence level (1 -CI) within the model but for simplicity we shall leave them all at 1.000 , that means we dont need to normalize the probabilities produced in the next column of NEWPROB((new(p) - so the model spits out probabilities as odds from those final models numbers where
Team A win - 1.31
Draw - 7.17
Team B win - 10.52
Note they all sum to 1.00 on the probability spectrum or 100% old fashioned money

We now want to combine these probabilities with the Bookmakers "true odds" calculated earlier with the overround stripped out logarithmically
How do we do this , averaging? -no ,geometric mean? -no - we use the logistic and exponential distributions as functions and of course because we are combining two sets of probs, we need to weight each set by significance - here i've used 0.45 for the model's probs and 0.55 for the "calculated true odds"
so carrying on the sheet from the MODODDSwCI (Models Odds without confidence interval)Column we add in the models odds and the "true odds"
(shaded light blue columns) then the logits and exponents work together to optimally find the best fit and combination. we can see that our final COMBIODDS are now
Team A win - 1.40
Draw - 5.85
Team B win - 8.68
Like this



finally comparing them to the Betfair market we see that the favourite and Home Team are +EV by 10.63% , if we were to bet them quarter Kelly we would stake a more conservative 3.53% of our Bankroll , if we were a bit more of a risk taker at Full Kelly we would stake 14.12% of our Bankroll. The Draw and Team B are -EV so no bets.


There are variations of Kelly type staking - one that i use incorporates variable stakes compounded with "edge obtained " layered over the top of the variable stake.

But what if the favourites two star strikers suddenly came down with injuries in the warm up before the match - very unlikely but used as an example again for simplicity, those odds would need updated
Here we use a Degenerate Distribution using bijection and reduction like this



As there are 3 outcomes the geomean of the original probabilities (the product of "COMBIODDS) is a decent generic to use in general but with experience of doing this kind of thing (putting a number on uncertainty, subjectiveness etc you get better at it) - for now we will use the Geomean of all 3 probabilities of what was calculated as "combi-odds" (as probabilities )-here it works out at 0.241390 - As it is a distribution all outcomes receive this value but in the next column "new ei" which is Bayesian for new information the team with the two star strikers with hamstrings or torn ligaments receive a value of 0.000, whilst the remaining probability mass and degenerative distribution value of 0.241390 receive a proportional amount of that mass according to the difference in their odds -in this case "the Draw" receives 0.59796 of that number or 59.78% whilst Team B receives 0.40204 of that probability mass or 40.20% which at a value of 0.241390 works out at 0.144342 for "the draw" and 0.097049 for "Team B- win"
We then use a simple Bayesian equation of (1-Degen.Dist)*(New ei)+Original Probability so for "the Draws case it would be (1-0.241390)*(0.237143)+0.17170 = an updated probability of 0.237143 or new updated odds of 4.22 - Notice now there is no value in the game when the new odds are compared to Betfair's odds and probably one to leave alone, except maybe Team B which has an updated probability of 0.1596 or odds of 6.27 Betfair has the Team B at 7.34 so in essence it is 17.34%+EV - Question is do you want to bet a team that is out modelled in all metrics and your only basis for betting them is the injuries to the two start strikers. In my book - NO - there has to be a reasonable amount of attraction to the bet in the first place. Team A are still the most likely winners , the Draw is the second most likely outcome and your thinking of betting a team that has been outplayed all season hence why they were originally 8.68 when the the two odds distributions were combined in the first place. No bet and there is never a last race, game , hand , round etc - there will be better opportunities down the road.

 

[DuckandDive]

For the last few years I've been going down the rabbit hole of determining value in terms of creating a range of horse race ratings, converting them to a tissue price and comparing with the live odds on offer. The concept is a simple one, but in itself can be frustrating when an obvious winner escapes because it wasn't a value price. The flip side is that the ones that are too short, despite having a stand out chance, bet beaten and a bet is saved.

The main reason for pursuing the value concept is the satisfaction of digging out a piece of information not known or not obvious at first glance, that can skew the ratings favourably and in turn create some value.

The importance of value is what is used to crunch the data/numbers and produce an output/outcome that is ahead of the market/public opinion. If the data is useless, outdated, inaccurate, then the output will be useless, even though you might get lucky here and there.

Ego can be a issue too. It the information isn't cross checked and examined, even the winning ones, then there's a misguided belief that the groly hail has been discovered and the rest is history.

Football is a big subject and if you find a niche then there will be plenty of markets to bet on for value. I like to look at football data and various websites during the season and still get surprised at some of the upsets when an away team out of form, beat an in form home team. In essence, it's likely the away team became value due to the home team being overbet. Would I have bet the away team? No, as a football fan, yes if I was a hardened value seeker over 1000's of bets.

I also play poker. You hear terms, "betting their hand for value". Implied odds and reverse implied odds. One player betting a value hand is another players showdown hand without putting another chip in the pot and willingly give up extracting value for a safer route. In the short-term, it's probably okay, but if it's a long-term game, it will impact the bottom line of a winning player and turn them into a losing player. The same can be said of horse racing and football betting. So I suppose that's the true importance of value.

 

[markfinn]

Its old saw this one - I would say -

Is value not generally reflected in the knowledge of the punter ? - is there such thing as a none value winner to those that know the result

 

[pawras]

For me value is in the eye of the beholder, pre race it is all entirely subjective opinion

 

[Outlander]

value of the holy grail of betting, perfect probabilities are impossible , the closer you can get , the closer you get to the holy grail.
Im never going to get close, most of the time when I spot value and bet (confirmed by subsequent market move) , the horse still manages to struggle home in last place. At that point I feel was it really value, doesn’t feel like it, where did I go wrong, then I realise I didn’t factor in the weight of my money on the horses back. To be honest this is the most important factor in determining any horses chance, I could get Frankel beat.

 

[gerry]

Well from last night study i have 5 horses that i think have chance today and noted them down and indeed bet them.
from last night till today there odd have went like this. 11/2 now 9/2- 6/1 now 6/1- 11/4 now 7/2- 3/1 now 4/1 - 4/1 now 4/1.
Looking at it only one has came with sway of money two have drifted and two have stayed same.
So you could argue i have got value in the first one where it has been shortened since i placed bets.
But the two i personnally thought had the better chances overall are the two who stayed the same price and possibly one drifter.
So now were in the dilemma of deciding whats value some will say the one where money has come for now but i didnt know money would come for it when placed bets.
Some will say the drifters as now getting better odds.
Some will say the two who stayed the same as i already said there the two i was most hopefull of in accessing races.

 

[mick]

value of the holy grail of betting, perfect probabilities are impossible , the closer you can get , the closer you get to the holy grail.
Im never going to get close, most of the time when I spot value and bet (confirmed by subsequent market move) , the horse still manages to struggle home in last place. At that point I feel was it really value, doesn’t feel like it, where did I go wrong, then I realise I didn’t factor in the weight of my money on the horses back. To be honest this is the most important factor in determining any horses chance, I could get Frankel beat.

I often feel its a great injustice that the more we may think we know then the harder turning a profit becomes. Fortunately i am still proving myself wrong in this respect but the feeling remains. I do not see obtaining value as the holy grail but it is a need if only to help swerve a years end loss. ! Your above beef is about not being able to back winners but a punter can back plenty and yet still show a loss, and under these circumstances obtaining value or failing to do so is prob the straightener.