Turf vs Dirt question

[steveb]

Originally Posted by DeltaLover

If the subject of the thread is how to calculate the final time of a horse that was beaten by a number of lengths, I cannot see how the surface is playing a role. The related parameters are the final time of the winner of the race, the distance of the race, the number of beaten lengths and the average length of the horse.

The formula I am using for this purpose is very simple and straight forward:

  HORSE_LENGTH = 3.
  
  
  @make_exception_safe
  def get_time_from_beaten_lengths(distance, final_time, lengths_beaten):
      """
      :param distance: Distance of the race in yards
      :param final_time: Final time in decimal format
      :param lengths_beaten: Number of beaten lengths in decimal format
      :return: the final time for the given beaten lengths
      """
      return final_time * (1 + lengths_beaten * HORSE_LENGTH / distance)

length margins these days are a function of time, not distance, thus the length of a horse is basically irrelevant in this case.
for instance the length of a length will be different depending on distance.
i have figured an average of about 2.62 metres equal a length, but the further the race the less it is and the shorter the more.

thus if dirt is slower than turf, then it should be obvious to smarter people than me why surface is a huge factor.

ask me the physical length of the average horse and i would have no idea of the answer, nor do i need to know.

[DeltaLover]

Originally Posted by steveb

length margins these days are a function of time, not distance, thus the length of a horse is basically irrelevant in this case.
for instance the length of a length will be different depending on distance.
i have figured an average of about 2.62 metres equal a length, but the further the race the less it is and the shorter the more.

thus if dirt is slower than turf, then it should be obvious to smarter people than me why surface is a huge factor.

ask me the physical length of the average horse and i would have no idea of the answer, nor do i need to know.

The length of the horse does not change as tance t. What changes is the corresponding distance from the winner of the race, since the horses are moving with different speed.

[steveb]

Originally Posted by DeltaLover

The length of the horse does not change as tance t. What changes is the corresponding distance from the winner of the race, since the horses are moving with different speed.

it changes because the longer the distance then the slower they are going on average as they pass the post, and that is because they use time to calculate distance, which i guess is nonsensical, but it's what they do.

(TIME_RACE / TIME_HORSE * DISTANCE - DISTANCE) / LENGTH_MARGIN

is how i have figured it, and i would show you the results if i knew how to post pictures from my own computer!
its a simple calculation when officials give both time and margin.

and it's just one more reason why proportion is the go, rather than any constant.

one does not need to know the length of a horse because it plays no part in how they calculated a length margin in the first place.
all they have done is say .16 of a second equals a length, or whatever figure any particular place uses.
in australia they all use different figures so that alone makes the value of a length all over the joint!

[cj]

Originally Posted by DeltaLover

If the subject of the thread is how to calculate the final time of a horse that was beaten by a number of lengths, I cannot see how the surface is playing a role. The related parameters are the final time of the winner of the race, the distance of the race, the number of beaten lengths and the average length of the horse.

The formula I am using for this purpose is very simple and straight forward:

HORSE_LENGTH = 3.


@make_exception_safe
def get_time_from_beaten_lengths(distance, final_time, lengths_beaten):
    """
    :param distance: Distance of the race in yards
    :param final_time: Final time in decimal format
    :param lengths_beaten: Number of beaten lengths in decimal format
    :return: the final time for the given beaten lengths
    """
    return final_time * (1 + lengths_beaten * HORSE_LENGTH / distance)

That isn't what the subject of the thread is, but that said, it actually could vary by surface depending on how fast the horses are finishing. The various photo finish companies all use different formulas to convert the difference between the winner's time and the also ran time into a beaten lengths number. Why they just don't give us the time of each horse I have no idea.

[steveb]

Originally Posted by MJC922

The part that 'just happens' in the states we call it class.

i am intrigued as to why you think my 'just happens' has anything to do with class?
i am awe struck!

[whodoyoulike]

Originally Posted by cj

That isn't what the subject of the thread is, but that said, it actually could vary by surface depending on how fast the horses are finishing. The various photo finish companies all use different formulas to convert the difference between the winner's time and the also ran time into a beaten lengths number. Why they just don't give us the time of each horse I have no idea.

This is probably one of the best ideas I've seen related to handicapping.

[steveb]

Originally Posted by cj

That isn't what the subject of the thread is, but that said, it actually could vary by surface depending on how fast the horses are finishing. The various photo finish companies all use different formulas to convert the difference between the winner's time and the also ran time into a beaten lengths number. Why they just don't give us the time of each horse I have no idea.

pretty sure there is a setting so that the judges at any particular track or jurisdiction, can set it where they like, as distinct from the photo finish company.
over here i have figured for western australia they use .16 seconds per length regardless of distance, going, class or anything else.

south australia, uses variable, sometimes .15 other times .17 or any number in between, and i have been unable to figure why they use which number, because i can't find any pattern to it.

the other states are all over the place too, which obviously means that a length means different things wherever you may be!

why they all don't just give the time is beyond my understanding as it is yours obviously
why take a number(time) that is correct, and convert it to something less correct(length)?

[whodoyoulike]

Originally Posted by steveb

there is nothing artificial about it.
it's all non-subjective and proportional and it just 'happens'.

one thing that has me intrigued, i often wonder how far advanced they would be in their time stuff in the states, if they measured in metric rather than imperial.
some things are just staring you in the face with metrics, that one would not likely notice with imperial.

I hope they don't change the measurement system over here because I'm used to handling inches and feet. I wouldn't know how to respond if a woman said "that doesn't look like 23 cm." other than to say I meant +/-.

[cj]

Originally Posted by steveb

pretty sure there is a setting so that the judges at any particular track or jurisdiction, can set it where they like, as distinct from the photo finish company.
over here i have figured for western australia they use .16 seconds per length regardless of distance, going, class or anything else.

south australia, uses variable, sometimes .15 other times .17 or any number in between, and i have been unable to figure why they use which number, because i can't find any pattern to it.

the other states are all over the place too, which obviously means that a length means different things wherever you may be!

why they all don't just give the time is beyond my understanding as it is yours obviously
why take a number(time) that is correct, and convert it to something less correct(length)?

In North America, it is set by the photo companies. It is also a closely guarded secret for some reason, but like you have said, it isn't too tough to figure out.

[Magister Ludi]

Originally Posted by cj

That isn't what the subject of the thread is, but that said, it actually could vary by surface depending on how fast the horses are finishing.

In the UK, e.g., the average finishing speeds on turf are as follows:

going___finishing speed (m/s)
>good_______16.2
good________14.9
<good_______13.5

[DeltaLover]

Originally Posted by Magister Ludi

In the UK, e.g., the average finishing speeds on turf are as follows:

going___finishing speed (m/s)
>good_______16.2
good________14.9
<good_______13.5

depends on the distance

[cj]

Originally Posted by DeltaLover

depends on the distance

This stuff is way off the subject though. I don't think anybody is really struggling to convert beaten lengths to time.

[steveb]

Originally Posted by whodoyoulike

I hope they don't change the measurement system over here because I'm used to handling inches and feet. I wouldn't know how to respond if a woman said "that doesn't look like 23 cm." other than to say I meant +/-.

look at the following equation and then tell me it would be easier to understand if it was using furlongs or yards instead of metres.

(1-(WIN_TIME/HORSE_TIME)^(RACE_DIST/1000))*1000

(1-(69/70)^(1200/1000))*1000 = 17.12

it fits in nicely when you want to keep things proportionate.
how do you do that using furlongs without converting first?

i doubt i even need to say what it is expressing, as it is pretty much self explanatory.
and it keeps things in proportion

for instance....................
(1-(67/68)^(1200/1000))*1000 = 17.62

which is .5 worse than the other even though they are both beaten by a second and assuming that the 68 and the 70 are equal(100) which of course they may not be.

[Cratos]

Originally Posted by whodoyoulike

This is probably one of the best ideas I've seen related to handicapping.

They cannot give time of the run up horses because they don't time horses, they time the race and measure the distances between horses at POC and the finish; and convert those distances into time.

This is a crude and inefficient method given today's technology.

Trakus or a Trakus-like methodology should be used industry wide.

[cj]

Originally Posted by Cratos

They cannot give time of the run up horses because they don't time horses, they time the race and measure the distances between horses at POC and the finish; and convert those distances into time.

This is a crude and inefficient method given today's technology.

Trakus or a Trakus-like methodology should be used industry wide.

This had nothing to do with run up, it was about not giving the final time of each horse from the photo finish equipment. Instead, the difference in time is converted to "beaten lengths" for publication in PPs and the time is never divulged. Trakus does both, gives time and a conversion to beaten lengths.