Derby and Performance Figures

[The Indomitable DrugS]

Thunder Blitz's prep was open lengths faster than Point Given's Santa Anita Derby romp - or Millenium Wind's tour de force on that crazy old KEE dirt track?

That pretty much only shows a glaring flaw with his variant as I understand it. Thunder Blitz was coming from Hialeah - had he ran his final prep at Thistle Downs his figure would have been huge because of the straight class par model.

[somerfrost]

Originally Posted by The Indomitable DrugS

Thunder Blitz's prep was open lengths faster than Point Given's Santa Anita Derby romp - or Millenium Wind's tour de force on that crazy old KEE dirt track?

That pretty much only shows a glaring flaw with his variant as I understand it. Thunder Blitz was coming from Hialeah - had he ran his final prep at Thistle Downs his figure would have been huge because of the straight class par model.

Again, quoting Dr Roman:
"The two approaches differ mainly in that BSFs are based only on the final time of a race while PFs are based on an integration of final time and fractional time. In other words, PFs incorporate a significant pace factor while BSFs do not. The general methodologies are similar to the extent that both use variants from an expected level of performance to fine tune the raw numbers. These variants from the norm may be derived by comparison with par values for the class of race or, in the case of BSFs, projecting an expected figure based on the past history of an individual horse."

[Port Conway Lane]

Originally Posted by somerfrost

Ok, I understand you want a multi-year comparison, somewhere in my files I have several years of same which led me to use PF's instead of BSF's. I started using PF's exclusively in 2005 so I didn't compare the two thereafter. If I can locate same, I will post....in the meantime, Dr Roman did a one year study with results posted at his site. The two methods were compared in a variety of ways but in reference to top 5 vs top 5:
2001 Derby
BSF:
Millennium Wind...114 (finished 11th)
Balto Star...112 (finished 14th)
Keats...110 (finished 16th)
Point Given...110 (finished 5th)
Congaree...108 (finished 3rd)
PF's:
Congaree...-76 (finished 3rd)
Thunder Blitz...-76 (finished 4th)
Monarchos...-70 (winner)
Balto Star...-69 (finished 14th)
Millennium Wind (finished 11th)
Again, this was a one year study and Dr Roman summarized results thusly, "No general conclusions about the value of BSFs or PFs should be drawn from these singular results. BSFs have stood the test of time. They are certainly a profound improvement over raw time as a measure of performance. Nevertheless, the results do suggest that other approaches may be at least as accurate and equally useful."

Yes this is what I was looking for. I was looking at it just a few minutes ago.
The link to the page is here.
http://www.chef-de-race.com/pfs/bsf_vs_pf.htm

He picked a good year for the comparison.

[Gate Dancer]

Dr. Roman's 'Pace Parameters for 2011 Ky Derby Preps' link on the main page is definitely worth looking at. It exposes horses or races that just won't stack up on Derby Day also.

[Mike]

I looked at the site, but I sure would like a summary before the Derby, as there is way too much info for me (tonight, anyway)

[Slewbopper]

Originally Posted by somerfrost

Actually, Dosage parameters haven't completely failed in predicting Derby winners....since 1991, only 5 winners have exceeded dosage parameters of 4.00/1.00:
Strike the Gold...(91) 9.00/1.30 (later adjusted due to sire appointed CDR)
Real Quiet...(98) 5.29/1.27
Charismatic...(99) 5.22/1.00
Giacomo...(05) 4.33/0.94
Mine That Bird (09) 5.40/1.19
Lots of folks rushed to discredit Dosage but to date the vast majority of Derby entries fit within parameters.

Prior to Strike The Gold in '91 every Derby winner had a DI under 4.00 going back to Clyde Van Deusen in 1929. During the 80s I was a believer in DI. Today I think it is irrelevant. There used to be quite a few Derby runners over the 4.00 limit years ago so there seemed to be something to it. Today there are fewer starters that are over the limit, and there have been 5 winners in the last 20 years being over as opposed to none in the previous 62 years. It is irrelevant now

[Dunbar]

Originally Posted by Slewbopper

Prior to Strike The Gold in '91 every Derby winner had a DI under 4.00 going back to Clyde Van Deusen in 1929. During the 80s I was a believer in DI. Today I think it is irrelevant. There used to be quite a few Derby runners over the 4.00 limit years ago so there seemed to be something to it. Today there are fewer starters that are over the limit, and there have been 5 winners in the last 20 years being over as opposed to none in the previous 62 years. It is irrelevant now

It was irrelevant before, too. Dosage is a classically bad use of statistics. It's meaningless to quote results BACKWARD to 1929 when the idea was created in the 70's.

--Dunbar

[Thunder Gulch]

Dr. Roman never created the Dosage Index as a handicapping tool, he just discovered the results when looking at the winners of the Ky Derby. If you understand what is is and how it reflects speed/stamina characteristics typically passed on by certain sires, it is an interesting study if nothing else. He didn't change the formula as so many naysayers want to believe, but he did change the status of certain sires as sample sizes helped draw firmer conclusions over the life of the stallions. It wasn't an attempt to excuse Strike the Gold's DI, it was Alydar gaining "Chef" status as a "Classic" sire, something it would be difficult argue against in retrospect.

[Indian Charlie]

Originally Posted by Thunder Gulch

Dr. Roman never created the Dosage Index as a handicapping tool, he just discovered the results when looking at the winners of the Ky Derby. If you understand what is is and how it reflects speed/stamina characteristics typically passed on by certain sires, it is an interesting study if nothing else. He didn't change the formula as so many naysayers want to believe, but he did change the status of certain sires as sample sizes helped draw firmer conclusions over the life of the stallions. It wasn't an attempt to excuse Strike the Gold's DI, it was Alydar gaining "Chef" status as a "Classic" sire, something it would be difficult argue against in retrospect.

I remember actually arguing with some dosage nuts about Strike the Gold, before the Derby. I was going to play him, but was told he can't win because of his high dosage. I tried to explain that because Alydar was almost certainly going to be a chef, with stamina points, that he would indeed be a qualifier, down the road.

The whole concept of Dosage, however, does make some sense. I think people should use a little sense and flexibility with it though.

Then again, if you have any clue about racing and pedigrees, one has no need for dosage.

[Slewbopper]

Originally Posted by Indian Charlie

I remember actually arguing with some dosage nuts about Strike the Gold, before the Derby. I was going to play him, but was told he can't win because of his high dosage. I tried to explain that because Alydar was almost certainly going to be a chef, with stamina points, that he would indeed be a qualifier, down the road.

The whole concept of Dosage, however, does make some sense. I think people should use a little sense and flexibility with it though.

Then again, if you have any clue about racing and pedigrees, one has no need for dosage.

Very true......regarding Alydar, Roman was very slow to upgrade his chef-de-race status. Easy Goer should have made that a no brainer.

[somerfrost]

Originally Posted by Slewbopper

Very true......regarding Alydar, Roman was very slow to upgrade his chef-de-race status. Easy Goer should have made that a no brainer.

Alydar should have been upgraded earlier but they do same by committee and that took time.