Turf vs Dirt question

[thaskalos]

Originally Posted by PaceAdvantage

Do you know why he stopped?

My guess is that he was a bit too "sophisticated" for us...or we were too unsophisticated for him.

[Tom]

He's out weighing horses across the country for his spring assault on the betting windows.

[highnote]

Originally Posted by cj

I did some research today that was pretty enlightening. I've always known turf finishes are tighter than dirt finishes in general, but I didn't know to what extent. The value of a beaten length in a turf race is much greater than a dirt race. It actually breaks out really clearly by distance, less than a mile and a mile and over:

< 1m Value of a beaten length in turf races is 1.6 times that of a similar dirt race

> 1m Value of a beaten length in turf races is 2.0 times that of a similar dirt race

I use different values for the two, but not to that extent. Beyer made and adjustment to use his 6.5 furlong chart for turf routes, but that is about the 1.3 to 1.4 range, not 2.0. I don't believe Rags or Thorograph or BRIS or Equibase differentiate between the surfaces.

This is definitely something I'll be digging into a lot deeper the next few weeks. It sure looks like also rans in turf races are being given more credit than they deserve by speed figure guys, myself included.

Check out page 51 of "The Compleat Horseplayer" by David Edelman. He has a statistics Ph.D. He says that if you add half the beaten lengths to the Beyer figure you get a more accurate figure since horses tend to tire a little less on the turf.

[Tom]

So a horse runs an 82 Beyer and is beaten by 4 lengths - you add

4/2 = 2 + 82 = 84?

[highnote]

Originally Posted by Tom

So a horse runs an 82 Beyer and is beaten by 4 lengths - you add

4/2 = 2 + 82 = 84?

Yes. He said he needed a way to account for the fact that turf races have tighter finishes and tire less than on dirt.

He did regression analysis to come up with an equation that showed the average velocity at various distances for a given amount of prize money.

His actual equation is more complicated, but said the Regression Effect suggests adding half the beaten lengths to the Beyer Figure (which is expressed in units of lengths) and this will improve the Beyer Figure's accuracy on turf races.

One caveat that I can think of is that Beyer says he is always tweaking his turf formula. So what may have been true about Beyer Figures at one time may not necessarily be true today.

[classhandicapper]

Beyer made some changes to his turf figures recently and I'm pretty sure beaten lengths adjustments were part of it. So I'd be careful making adjustments that may have helped in the past until you have tested if it still helps now.

At this point, calling turf figures "speed" figures is kind of silly.

Everyone breaks out a lot of races for slow paces, most make adjustments for beaten lengths, and they sometimes have to make figures for horses that are first time turf in isolation because there are no other similar races at that distance on that day etc..

Turf figures are really often a kind of class figure that uses prior figures when available to enhance an educated guess at the quality of the field and race. The time is often inconsequential.

I'm not complaining about that. You do what to can to produce positive results. They just aren't speed figures.

[steveb]

Originally Posted by highnote

Check out page 51 of "The Compleat Horseplayer" by David Edelman. He has a statistics Ph.D. He says that if you add half the beaten lengths to the Beyer figure you get a more accurate figure since horses tend to tire a little less on the turf.

edelman did stuff for woods at one stage, but then was made persona non grata is what i was told.

[steveb]

Originally Posted by classhandicapper

Beyer made some changes to his turf figures recently and I'm pretty sure beaten lengths adjustments were part of it. So I'd be careful making adjustments that may have helped in the past until you have tested if it still helps now.

At this point, calling turf figures "speed" figures is kind of silly.

Everyone breaks out a lot of races for slow paces, most make adjustments for beaten lengths, and they sometimes have to make figures for horses that are first time turf in isolation because there are no other similar races at that distance on that day etc..

Turf figures are really often a kind of class figure that uses prior figures when available to enhance an educated guess at the quality of the field and race. The time is often inconsequential.

I'm not complaining about that. You do what to can to produce positive results. They just aren't speed figures.

too many assumptions.

[classhandicapper]

Originally Posted by steveb

too many assumptions.

What am I assuming?

We already know that most US figure makers break out WAY more turf races than dirt races due to very slow paces. They have to or the final time figures would be meaningless as a representation of the horses' ability. This has been widely discussed.

We already know that at least some US figure makers don't use the same beaten length charts for turf as dirt because of the different race developments and tighter margins. Beyer has stated that and CJ has discussed some of those issues in this and other threads.

There are unquestionably days in the US when there is either a single turf sprint or single two turn turf race on that course and it's filled with horses that are first time starters or first time turfers about which you have very little insight for figure making.

Since public figure makers are in the unenviable position of having to provide a figure, they often base it on whatever prior evidence they do have and not necessarily on the clock because there is no means of determining the track speed accurately. It's a best guess not based on the clock. This is a regular problem in the US.

That's kind of what class handicappers at Timeform Europe do. They look at the horses' past records, watch the race, figure out who they think delivered their best run, and create a class oriented Timeform Rating for the horses based on that past record, today's finish, the weights etc... It's not all about the final time.

To me, when you call something a speed figure, you are talking about the final time. That's means it's not a projection of how fast you think the horses might have run if the pace was more reasonable etc... When you do that, it's more of performance figure.

Again, I have no problem with it. The idea is to help players evaluate the horses. It's a definition issue for me.

[andicap]

Originally Posted by Tom

No surprises here, Robert.
When CJ had just his own private group of users, he was always coming up with new things, new ways to use things, and trying them out.

]


(SIGH) Those were the days Tom when we had CJ's figures all to ourselves.