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There are many things that relate to odds compiling Tommy, it is impossible to do it from ratings alone.
Value Is EverythingThis
https://betting.betfair.com/horse-racing/bloggers/simon-rowlands/post-222-040810.html
works only when ratings are quite closely grouped, such as in handicaps, but may give you some ideas.
Hi All
Can anyone show me how in baby steps to take a horses rating and give it oddsI have looked into, or am aware of, a number of ways of converting ratings to odds, including by Monte Carlo simulation (all possible results are established from all horses’ past performance ratings) and through Markov Chains (an array of past performance ratings can be expected to lead to other performance ratings with varying probabilities).
The approach described below comes as a result of one correspondent pointing out to me that the rather complicated process I was using was similar to a simpler one described by Don (“the Australian Phil Bull”) Scott. This is something of a hybrid of the two approaches.
Baby Steps?
Thanks for the good crack. Time for me to move on. Be lucky.
Those are the footsteps of adults but about as youthful as you’re likely to find
I recall the maths (math?) boffins who contributed to Smartsig mag and its forum picking their way through this minefield and although recall of detail is vague, do remember natural logarithms and chi-squared distribution entering the fray, in addition to Monte Carlo etc
As Gingertipster has pointed out attempting to convert master ratings (RPR, Timeform etc) to odds – if this is what the OP meant – is micturating-into-the-wind as such ratings are no more than bare ‘form’ ratings so do not take into account the make/shape/pace of the race you’re evaluating; and the effect those and other variables have on the ‘form’ the horse has shown itself capable of can be very significant
Those are the footsteps of adults but about as youthful as you’re likely to find
I recall the maths (math?) boffins who contributed to Smartsig mag and its forum picking their way through this minefield and although recall of detail is vague, do remember natural logarithms and chi-squared distribution entering the fray, in addition to Monte Carlo etc
As Gingertipster has pointed out attempting to convert master ratings (RPR, Timeform etc) to odds – if this is what the OP meant – is micturating-into-the-wind as such ratings are no more than bare ‘form’ ratings so do not take into account the make/shape/pace of the race you’re evaluating; and the effect those and other variables have on the ‘form’ the horse has shown itself capable of can be very significant
There is no easy solution it just seemed a bit beyond the Baby Steps process requested.
I prefer to keep my calculations as simple as possible these days. My University Mathematics are largely forgotten these days. The Calculus, advanced Trigonometry and juggling with imaginary numbers partial differentiation etc faded away through lack of use over 35 years.
From my point of view it’s easier to let the ratings people do their job and then consider if I feel they have over or under rated a horse. Likewise with odds. There isn’t a lot of point in my mind in compiling your own book for every race. It’s time consuming for a start and you can’t bet on your own odds. I wait to see what odds are offered and then decide if I think there is a value bet to be had, based on my own feelings about the contenders.
The type of races I tend to aim at don’t lend themselves to ratings and speed figures anyway. I tend to be looking for horses who will make significant improvement, for experience, age, increase in distance, or a combination of all these. I will generally also be looking to take on the bigger names in the training ranks, in the belief that their stables are usually over-bet and often blindly followed, offering poorer value overall.
If I start seeing punters sitting at the table in a seedy betting shop using betting slips for calculating (d2y/dx2 -logZ/sin(a)cos(lettuce) black and tan root ginger)
, I’ll know I’ve fallen behind the numbers men big style.Thanks for the good crack. Time for me to move on. Be lucky.
Aye. The more honest answer would have been “Baby steps? You have to be kidding”
Thought something there (probably not Markov chains and MCsim, admittedly: I didn’t re-read the piece) might spark something.
There must be some theoretical race in which horses are rated 100, 99, 98, 97 etc and you “should” price them 5/1, 6/1, 7/1 etc, but it’s nowhere near that simple in the vast majority of cases.
As has been pointed out, the method put forward falls down once you get much of a skew in distribution.
A simple system which you can tweak and adjust to your final opinion is once you have done your workings, rate runners between a high and low number. Could be 1-10, 1-5, 1-100 etc. Once rated each horse, total the numbers then divide the total by each rating to give you the odds (divide rating by total for percentages).
Example
A – 10 – 36/10 = 3.6 (13/5) / 10/36*100 = 27.77%
B – 7 – 36/7 = 5.14 (round down to 4/1) / 7/36*100 = 19.44%
C – 5 – 36/5 = 7.2 (round down to 6/1) / 5/36*100 = 13.88%
D – 5
E – 4 etc etc
F – 3
G – 2 etc etc
Total 36It can be a sound method for giving you a base to adjust accordingly.
Hi All
Can anyone show me how in baby steps to take a horses rating and give it oddsTommy,
Are you talking about a “rating” given by an organisation eg Timeform or Racing Post? If so there is no way of converting these ratings in to odds on their own, because so many other aspects of form contribute to a horse’s chance.Or are you talking about your own “rating”?
If your own rating, what is this “rating”?
Is it just a form figure, a rating you believe the horse is capable of given ideal (not necessarily prevailing) conditions and pace? If so, again there is no way of convertion, for he same reasons.Or is it a “rating” devised for the particular race concerned? I suppose you could say I convert my own “rating” in to “odds” if we’re talking about my “percentage rating”.
If you’re looking to transfer a “rating” in to “odds” then the rating of all horses in a race should not be concerned with how good a horse is in “ideal” conditions… but instead what rating it is capable of in the prevailing conditions in that one particular race and how likely it is of showing that form. So needs to include everything that goes towards its chance. ie the particular race’s trip, going, likely pace/how rival horse’s way of racing will suit or will not suit each horse, time of year, course, jockey, trainer form, jumping ability/draw advantage and temperament… However, it is impossible to have a totting up process by having an “out of” figure for each aspect of form. Because each aspect is more or less important to the individual. ie For a horse with a very poor temperament then “temperament” will be a big part in the horse’s chance; where as for another horse with a good temperament but highly unlikely to stay the trip – temperament will hardly come in to it, yet distance has a big part to play in his “chance”. Needs to be a subjective, methodical assessment of every horse.
If you are capable of doing this… Make the sum of all runners add up to 100. ie Make the “rating” a percentage chance of winning.
eg in a particular 4 horse race:
If you believe B has three quarters the chance of A
C has half the chance of A
D has a quarter the chance of A
Then….
A = 40%, B = 30%, C = 20% and D = 10% because the sum of all runners needs to add up to 100…. 40 + 30 + 20 + 10 = 100 (100%)Then, convert the percentage in to odds…
40% = 6/4, 30% = 9/4 (almost), 20% = 4/1 and 10% = 9/1. So those are the “odds” you should be trying to beat in that particular race.Value Is Everything
, I’ll know I’ve fallen behind the numbers men big style.
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