Can't say they aren't worthwhile, but I've only been exposed to the average daily variant approach and every study I have ever done has shown that using a par without a daily variant works better.

Actually FAR better.

Now, just to be clear, I am not a guy who would put time into building a real, race-by-race variant that is dependent upon the true skill of the variant maker. I give honor to such people.

If you are that person... making an estimate of what each horse could do and comparing each to the other, considering post position, jockey impact (both good and bad), trips, and all the other complications, I am humbled by your skill.

If you try that and they don't work well, then I honor your effort.

But, alas, too much for me.

Just to be clear, about what I said elsewhere, I am saying that every attempt I ever did to make a computational daily variant failed badly when compared with using simple ratings derived from par for the track.

As most are aware, the Average Daily Variant is flawed, simply because the horses that run on Wednesday are (as a general rule) not as strong as those who run on Saturday.

The logic has typically been to apply an adjustment to each day of the week.

However, even that fails because not all Saturdays are the same caliber of races.


The solution would be to build a Strength of Field Rating for every single race, and then address the issue on a daily basis, asking the question, "How strong was this day?"

However, the challenge is not over there because the very definition of the fast/slow-ness of each race is in question.

This is best evidenced is found in the improvement of my own par times.
A little over a decade ago I committed to LONG-TERM IMPROVEMENT in my par making.

I designed something I called The Speed Reliability Index. (SRI)

Year over year I began making changes.

The first thing I noticed was that the *1ST CHALLENGE CALL of the eventual winner of a race made a huge difference in the final time.

IOW, winners that challenged for the lead at the 1st call resulted in faster final times than winners that did not get their heads within a length of the leader at the stretch call.

Of course, this is all very logical.

When a horse is on the lead wire-to-wire the time will be faster than when he's (say) 8 lengths back at the first call.

I began weighting the races in the sample using a 4-3-2-1 approach.
That is, races where the winner of the race mounted their 1st challenge at the 1st call were weighted at "4," while winners who did not get within 1 length until the last fraction were weighted as a "1."


The improvement was both immediate and drastic.
So much so that each year I changed the weightings to even heavier weighting of the EARLIER CHALLENGERS.

It went from 4-3-2-1 to the current 9-5-2-1!

On a higher level, the impact of this change can be seen in our internal Flagship Rating, simply called "RTG" in our software.

Note that RTG is a "Composite Factor;" a combination of 32 other factors, many of which are Composites themselves.

Speed Ratings make up the biggest part of RTG.
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Think of RTG as being like the BRIS PRIME POWER rating, as well as HDW's PSR and CPW (an older version of PSR).

Back when I started, PSR, CPW and BRIS PP, were all hitting about 29-30% winners on the top ranked horse. (Now about 31%.)

RTG was at 24.6%.
Today, RTG stands at slightly over 31%, with the highest return of the 4 listed numbers. (That's because it does not correlate with the tote quite as much as the other numbers.)


So, what do you do?
The answer seems to lay in weighting each race by the running style of the winner.

But even that has problems.
It is simply difficult to look at a day with 8 races on the card:
4 sprints
2 routes
1 4f race
1 turf race

And make a viable daily variant.

Add the complexity of maiden races, first-time-starter races, off-track for the 1st few races... and a myriad of other complications... and you have a system that is ripe for over-inflating or under-inflating the races.
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[SIZE="4"]That is why every test I have ever done leads me to NO VARIANT as the best approach.[/SIZE]



* 1ST CHALLENGE CALL must be credited to Jim Cramer, the great mind behind HDW's ratings.