Contender Selection/Eliminations
 

In the first stage of race analysis, the color designations for top 3 are based on APV and CR. That immediately points out entries that may be glaringly deficient in this area (45%, 50%). Are there any generic guidelines for eliminations/contender designations at this point, using only the APV and CR?

Individual races vary, of course, but I am wondering if anyone has done any serious testing of the APV and CR designations. For example, how often does an entry with APV and or CPR 50% or less actually win? Or 60% or less? And how much confusion is introduced in the readouts by including such an entry as a contender?

Information, insights, suggestions, and ideas will be appreciated.
Thanks

J,

I haven't seen studies. And I would make NO initial eliminations based on APV or CR. When CR doesn't land you on an obvious favourite, it touts a horse who used to be better than it is recently. Whether it's a Win pool contender today depends on form cycle and energy measurements. Perhaps a good CR horse returning after a long layoff is an in-the-money contender.

I suspect there is a reasonable co-relation between, say, top half CR (or perhaps also APV) and win rates, but I also suspect the corresponding average mutuels are disappointing because the components of CR (Average Purse Value the horse competed successfully for, in-the-money %) is so visible to the public. Far less visible are energy disbursement interrelationships, the matchup, the usefulness of accepting lines beyond the last one (or beyond the last 2).

Myself, I sometimes use Top 3 CR horses as a place to start in manually choosing lines - i.e. who are the principal actors today. Often these will have the upper ranges of Total Energy, and as I add the rest of the horses, if they fall significantly below these (often) upper TE ranges, I eliminate them just as fast (unless there are significant match up issues - very early horse, very late horse, opposite E/L graph standout, etc). But I enter a line or lines for almost every horse.

I would not hesitate to remove from Win consideration any higher ranked CR horse who did not cut it on Total Energy. I may re-include them for ITM if they also have some reasonable counter-energy readouts, or are heavily bet. Whether this adds confusion to a practitioner who over-relies on this readout, is for one's own record-keeping and feedback loop to advise.

HTH.

Ted

Apv/cr
 

Thanks for the clarification. I watched a YouTube video clip of a race you handicapped, noticed you started with the top APV/CR, then (much to my surprise) entered all or most of the entries as possible contenders. I started doing the same thing, it worked well for awhile, then I hit a couple of races in which entering low APV/CR entries tweaked the ratings (what used to be called "cheap speed"--fast fractions and final times at a lower grade race). That is, the entries had high TE, but were "apparently not competitive at today's class level."

In reading and re-reading the Follow Up issues, there are repeated references to only entering true contenders, with 5 or possibly 6 being normal. I have no conceptual issue with entering every horse and letting the application do the sorting. TE is a value tightly associated with the sum of the fractional fps rates; that puts cheap speed high on the TE rankings. I'm curious if there is some (approximate?) way to distinguish contenders and non-contenders using the APV/CR when those entries rate high on TE.
Thanks

J,

Sartin's thesis was/is: speed = energy = class. And some would say that using adjusted Total Energy (TE) alone (though I use the corollary of Perceptor/Primary Line Score) you get a Win % in the golden ratio range (~62%) from the top 3 and that this is sufficient measure of 'class' to nudge you towards breakeven or positive ROI.

Perhaps the 'cheap speed' you observed could be discounted by other means - are you able to cite an example (e.g. from the Demo Database?) Of course, single instances will always occur, and sometimes 'local knowledge' does the trick (ask me how I know to discount Ft. Erie speedballs at Woodbine :o ). But this is a reason I urge caution using CR (APV, consistency) as a measure of 'class'. Sartin had dropped CR/APV after the mid-1990s for much the same reasons I'm urging caution - it suppressed more obscure horses with 'actual class' represented by energy measures and disbursement relative to today's competition. I reintroduced it as much as a measure of 'back class' or a rationale to seek a line further back, as anything else.

On re-reading your original post, I think you may be asking if one risks much (or have studies been done) by eliminating from Win the bottom half (or so) of the CR/APV range. Interesting study, now that I think of it. Compound that with Total Energy or the VDC rank and you could perhaps be on to something.

Perhaps the closest I can come to advice re the keeping/eliminating horses based on CR, is when considering eliminating a 6th ranked horse relatively tied on other counts with a 5th ranked horse, I'd err on the side of CR. Or, horse has high TE, high CR but layed off 180+ days (non-Stakes): I'll move it out of the Win slot but consider keeping for ITM. Or, the high TE and high CR rating comes from a few months ago and I'm trying to decide if I should go back those 4 lines. Something like that.

Examples might help.

Ted

Here are typical results for a year. APV "10" = Today's Purse

APV 1-7 (53,596 HORSES) (4731 WINNERS=9%) ($16.21 AVERAGE PRICE)
APV 8-15 (194,771 HORSES) (24,877 WINNERS=13%) ($12.05 AVERAGE PRICE)
APV 16-20 (29,519 HORSES) (4788 WINNERS=16%) ($9.79 AVERAGE PRICE)
APV 21-25 (10,210 HORSES) (1950 WINNERS=19%) ($8.92 AVERAGE PRICE)
APV >25 (8056 HORSES) (1628 WINNERS=20%) ($8.26 AVERAGE PRICE)

Naturally, first time starters without an APV are not included.

Hope this is helpful.

That is extremely helpful. Thanks! Stated another way, 91% of entries with APV in the range 1-7 (10-70% of today's purse) failed to win. I know there are always exceptions, but I have a very strong feeling that they would be in the 6-7 range, rather than 5 or lower.

APV is seriously tweaked (especially in East) by state-bred bonuses, and is not as useful as it may once have been as a standalone factor. However, in combination with the CR, it may be useful in contender selection.

Again, thank you for the information.

Distinguishing contenders and non-contenders using APV/CR when those entries rate high on TE depends on the values used in CR. The CR I developed for my own use in the 1980s (and gave to Dr. Sartin and anyone else who wanted it) was (to the best of my knowledge) the first realistic compounding of values because it was tiered by race class.

Basically, APV + ITM is a tweaked APV--the values are very heavily weighted toward APV. Because APV is often artificially inflated by state-bred races and other anomalies, it tends to overshadow otherwise significant differences in ITM values. The CR I used combined APV + ITM% + Win% + EPS as a value appropriate to the class level of the race. For minor tracks, the increments of EPS might be $500, while the same value might be increments of $1000 to as much as $5000 at higher grade tracks. The whole idea was to make the EPS an "equivalent" (in magnitude) value for compounding.

As you know, one of the most misleading outputs is APV calculations on lightly-raced entries. To avoid the "division by zero" error in the old DOS programs, if there were no wins, a show or place would be moved to the win position to avoid the error in calculation. That seems to have become so accepted that no one questions why it is done, or what effect it has on the APV calculations (and database records of APVs).

After that regretably long-winded prelude, the short answer is that a CR can be very useful in recognizing "cheap speed"--an entry with high TE from a lower grade race, entered today at a higher grade in which it is unlikely to "run to its numbers." One of the most stunning insights about wagering is that every losing bet you don't make is the equivalent of picking 50% winners at even money.

Thanks

Thank you both, FTL and J2EE!

Ted

You are correct, but not specifically in the east. This is true in state bred races in "any" state. The way to handle this is, if you are able to determine that a goodly portion of the horses earnings come from state bred racing, you can lower the APV by 20% as that is approximately how much the purses are inflated in state bred races.

Very interesting. This is much like the "surrender option" in blackjack, where losing 50% on a hand that has a long term expectation of losing more than 50% actually increases profits. (This assumes one "knows" when to exercise the option correctly ;))

Anecdotal evidence
 

Hi J2,

The late Guy Wadsworth, who wrote most of the late Sartin software told me that 90% of all winners were in the top five of APV, in all classes, and although he presented no validating charts or evidence, this seems accurate to me as a ballpark figure.

Just anecdotally, I've found APV to be most useful at the high end, above GR. II, and the low end, below 10k - not incidentally the areas in which the various pace numbers, including TE, tend to be less useful. It's not unusual to get a stakes race exacta by simply boxing the top three APVs. BTW, this is true for winners only sub-10k, not place and show necessarily.

The main problem with APV, as FTL's useful chart indicates, is that it's a very obvious and overbet factor, with subsequently no wager value under most circumstances. As far as its utility in eliminating 'false positive' TEs with cheap speed, it's not as accurate as simply eyeballing the PPs. In general TE 'false positives' are more likely to fall into the category of 'herd' horses - those that generally run well but prefer to lose. You can recognize them by the preponderance of yellow and green in their PP finish positions.

Best of luck.

Cheers,

B Jennet

That is a fair approximation that will work in most cases. The question is, how do you determine the proportions of state-bred to open races when some or most may be in older races (early in the year) and not show up in the latest PP lines? A similar situation exists with f-claimers; some have same or near-same purses as open, but are generally considered about 20% "less in competition" (or claiming price, etc.).
Thanks

Exactly, with the caveat that the Surrender option is used appropriately. Unless you are counting, and know the various probabilities involved on a hand-by-hand basis, Surrender is a poor choice.
Thanks

I agree. It's a tough call. As I said "IF" you can make the determination then you can make some adjustment, otherwise, you're kind of forced to go with what you have. :(

That's what i said. :D

I agree in general, with an added note. A drop in class to win is fairly common, especially at minor tracks. Despite a good race that makes it seem the entry is in top form, when it returns to its "normal" class level (where it is relatively safe from hostile claims because it is overvalued) it tends to run more poorly than its numbers from the lower race might indicate.

Despite its many failings, the APV can still be used as an indicator--even if what is indicated is a the necessity of taking a closer look at the PPs.

I understand that, but other readers may not. They may think that all you need to know are the relative (generic) probabilities that the dealer's hole card will be such-and-such, based on full deck calculations. Like most other things in life, it isn't quite that easy to know when to use the Surrender option.
Thanks

Actually relatively easy
 

J2,

Not to let this thread drift too much, but just wanted to add a couple of comments for recreational blackjack players. I played the game professionally during an earlier period of my life and continue to derive some of my income from it. As both J2 and FTL mention, unless you're counting cards, you should never take either the surrender or insurance options, which are extremely valuable under the right conditions. However, if you are counting, it's a relative no-brainer to make either of these decisions - certainly compared with almost any decision that needs to be made in horserace handicapping, a much more difficult endeavor.

Cheers,

B Jennet

Yes
 

J2,

I use it in generally the same way.

B.