On the DRF's Speed Rating-Track Variant

[VigorsTheGrey]

In the DRF for 9Sep Kentucky Downs Race 3
Horse "Sekondi" shows 4 PPs ran at 1 mile at Santa Anita
All run on fast track, his Speed/ Variants were
72-23
77-17
62-27
63-30

Why is the track variant so high on surfaces listed as "fast"....?

Is there a variant Baseline that all the dirt tracks are measured against even before any moisture further slows the surface....?

[Augenj]

Originally Posted by VigorsTheGrey

In the DRF for 9Sep Kentucky Downs Race 3
Horse "Sekondi" shows 4 PPs ran at 1 mile at Santa Anita
All run on fast track, his Speed/ Variants were
72-23
77-17
62-27
63-30

Why is the track variant so high on surfaces listed as "fast"....?

Is there a variant Baseline that all the dirt tracks are measured against even before any moisture further slows the surface....?

From the DRF Tutorial here -
http://www1.drf.com/flash/drf_pp_tutorial.html

[FakeNameChanged]

Originally Posted by Augenj

Here's why I do that for the speed component of my ratings. It's just one of eight components.

Let's say a horse has 2 races, one of them on a very slow track and the other on a very fast track. Both races are equal in class, distance, and surface. He finishes 1st in both of them.

Slow track - 50 speed + 50 variant = 100 adjusted speed
Fast track - 95 speed + 5 variant = 100 adjusted speed

It's obvious that he performs equally well on both slow and fast tracks. This is a gross simplification but can be used to get a slightly better (2 percent) win per cent if you average his adjusted speed figures over just averaging the speed figures without the variants.

The 2 percent comes from thousands of races at eleven major tracks over one year. That 2 percent value will vary by track and it's been a long time since I visited the stats behind it since speed is only a small piece of the THA ratings.

I also adjust the variant by multiplying it by 0.75 before combining it with the speed figure. This is an optimized figure from thousands of race calculations and is obvious when seen at the peak of a Bell Curve.

Not doubting your figures. Did you plot your calculations and bell curve against another speed figure such as Beyer, Bris or Equibase or a par value that you established? It jives with some work I've done a long time ago, but only for track variants near the middle of the bell, for instance, var's. from 13 to 27.

[Augenj]

Originally Posted by Whosonfirst

Not doubting your figures. Did you plot your calculations and bell curve against another speed figure such as Beyer, Bris or Equibase or a par value that you established? It jives with some work I've done a long time ago, but only for track variants near the middle of the bell, for instance, var's. from 13 to 27.

It was with my calculations for the speed base factor.
I bias the Equibase speed figures with a percentage of variant (0.75), square root of purse, same surface as today, and same distance as today.
Each of these produces a small improvement in speed win percent.
Like I said earlier, speed is only one of 8 factors that I use to calculate an overall rating.

[cj]

Originally Posted by VigorsTheGrey

In the DRF for 9Sep Kentucky Downs Race 3
Horse "Sekondi" shows 4 PPs ran at 1 mile at Santa Anita
All run on fast track, his Speed/ Variants were
72-23
77-17
62-27
63-30

Why is the track variant so high on surfaces listed as "fast"....?

Is there a variant Baseline that all the dirt tracks are measured against even before any moisture further slows the surface....?

Have you not read the thread you started? It was detailed how the variant is created, even debated some.

[VigorsTheGrey]

Originally Posted by cj

Have you not read the thread you started? It was detailed how the variant is created, even debated some.

So are the points that are shown as the track variant for a runner "accumulated" or "averaged" from all races run that day at that distance on that surface...?

It must be averaged, because there is no way the example runner could get an 03 variant from one race alone, since he was 4/5ths off par to begin with, and adding the points of all races would lead to a Variant higher than 03...



http://www.paceadvantage.com/forum/a...2&d=1504946978

[cj]

Originally Posted by VigorsTheGrey

So are the points that are shown as the track variant for a runner "accumulated" or "averaged" from all races run that day at that distance on that surface...?

It must be averaged, because there is no way the example runner could get an 03 variant from one race alone, since he was 4/5ths off par to begin with, and adding the points of all races would lead to a Variant higher than 03...



http://www.paceadvantage.com/forum/a...2&d=1504946978

Averaged.

[VigorsTheGrey]

Sometimes there is no variant next to the Speed Rating, or just a dash/ blank space...any thoughts on why this may be...?

Also, it is not that uncommon to see a speed rating over 100, so does this mean that the runner ran faster that race than the best time in the last 3 years....?

...And then does the 100 baseline speed rating adjust higher automatically and become a new baseline...?

Also, I see speed ratings that are above 100 but the Beyer number for the runner is pretty low...One would think that the horse would get a relatively high Beyer if it bested the fastest time in 3 years....but no...what gives..?

[DeltaLover]

Originally Posted by VigorsTheGrey

Sometimes there is no variant next to the Speed Rating, or just a dash/ blank space...any thoughts on why this may be...?

Also, it is not that uncommon to see a speed rating over 100, so does this mean that the runner ran faster that race than the best time in the last 3 years....?

...And then does the 100 baseline speed rating adjust higher automatically and become a new baseline...?

Also, I see speed ratings that are above 100 but the Beyer number for the runner is pretty low...One would think that the horse would get a relatively high Beyer if it bested the fastest time in 3 years....but no...what gives..?

As discussed in the previous posts and in many others in the board, DRF track variant / speed rating consists of an antiquated approach, so I do not think is a good idea for anyone to spend time trying to analyze it. If you are a recreational handicapper you can use a commercial approach (CJ's figures is probably your best choice) and if you are more serious about the game your best option is to build your own historical database and learn how to derive your custom figures directly from raw data.

[VigorsTheGrey]

Originally Posted by DeltaLover

As discussed in the previous posts and in many others in the board, DRF track variant / speed rating consists of an antiquated approach, so I do not think is a good idea for anyone to spend time trying to analyze it. If you are a recreational handicapper you can use a commercial approach (CJ's figures is probably your best choice) and if you are more serious about the game your best option is to build your own historical database and learn how to derive your custom figures directly from raw data.

Silly me, I thought that is exactly what I was paying the folks down at the Daily Racing Form $11 a copy to do...to build a historical database and derive custom figures from raw data, that is...

But I understand what you mean...I suppose every serious player eventually arrives at that same conclusion..It's just that some act on it and change their pattern, while most do not...

[Tom]

Custom figures.....you want Cher or Mama Cass?
DRF offers both.

[PaceAdvantage]

Originally Posted by VigorsTheGrey

Silly me,

Yes

[VigorsTheGrey]

Originally Posted by VigorsTheGrey

Sometimes there is no variant next to the Speed Rating, or just a dash/ blank space...any thoughts on why this may be...?

Also, it is not that uncommon to see a speed rating over 100, so does this mean that the runner ran faster that race than the best time in the last 3 years....?

...And then does the 100 baseline speed rating adjust higher automatically and become a new baseline...?

Also, I see speed ratings that are above 100 but the Beyer number for the runner is pretty low...One would think that the horse would get a relatively high Beyer if it bested the fastest time in 3 years....but no...what gives..?

Unfortunatley, I'm not in a position at the moment to begin to change my pattern of buying the hard copy Daily Racing Form...maybe some day in the future I can devote the time and energy and knowledge to built my own custom database...

For the time being, I prefer to struggle with what is in the Form like the Speed Ratings / Variant, Beyer Numbers, and Pace Flow Icons, and now the TimeformUS Pace Ratings...

My main struggle is trying to determine if these (4) indications are mutually exclusive or if they can be combined in some fashion...

...As for the Speed Ratings being antiquated, I don't see that, because they are only time comparisons to a known value for each track and distance...so what is to become antiquated about that except for the timing is done in 5th's instead of decimals...

[classhandicapper]

Originally Posted by VigorsTheGrey

...As for the Speed Ratings being antiquated, I don't see that, because they are only time comparisons to a known value for each track and distance...so what is to become antiquated about that except for the timing is done in 5th's instead of decimals...

The methods for measuring how times at different distances compare and for measuring how fast the track was playing have improved since the DRF Speed Rating and Track Variant were invented. As I understand it, they only remain in the paper because a subset of customers would get very upset if they were removed. But internally, no one I know considers it especially useful info.

[cj]

Originally Posted by classhandicapper

The methods for measuring how times at different distances compare and for measuring how fast the track was playing have improved since the DRF Speed Rating and Track Variant were invented. As I understand it, they only remain in the paper because a subset of customers would get very upset if they were removed. But internally, no one I know considers it especially useful info.

I keep hearing about this subset, but surely most of them are no longer with us!