Sliding variant or slippery slope?

[Kingfisher]

Clearly the track surface was changing through the course of the day. But each time a decision is made to change the variant you decrease the sample size. And if the track is really changing, even between just one or two races, and the variant is similarly adjusted, then the numbers get less and less accurate because the error rate goes up (normal consequence of reducing the sample size). But there isn\'t any other way to deal with it, since there is no way to collect more data (more races) for the given conditions. My only suggestion then would be to do something similar to what the animal breeders (cattle) do. That is, when they assign breeding values for sires (called EPD\'s, for Expected Progeny Differences), they also include an Accuracy number, expressed as a percentage, that reflects the sample size that the EPD value is based on. In other words, for a ten race card, a variant that is constant through the day (or multiple days?) gets say 10/10, or 1.00.  If the variant for a race is based on fewer races, say 4/10, then the accuracy stat would be 0.40. Then the handicapper can make the decision as to how much faith to put into the number. The numbers-maker will have done his level best to provide an accurate number, given the total information (however sparce) available to him.



Post Edited (06-10-04 03:00)

[TGJB]

Even when the track speed essentially is staying the same, there are small adjustments we make race to race-- could be because of wind gusts, slight differences in moisture content, etc. One of the interesting things about doing this is that situations come up often where you can see exactly what the race should be, absolutely rock solid, first time through, without looking at the surrounding races at all-- a couple of years ago we posted the Peter Pan on this site (should still be in the archives), and almost the whole field paired their recent tops. There are other times when you can have 2 or 3 races in a row with lightly raced horses, some of them obviously jumping up, and it\'s a battle.

This is one of those things that is difficult to describe to someone who has not done it. Most of you out there who have made figures have probably used pars, which means you are basically just going off the winners, which is indeed a small sample. The ones who have made projection style figures have not had the advantage of using wind and ground, even if you do use weight. Point being, when you do it the way we do, the sample size (the whole field, lifetime histories) is not that small, and the figure histories of the horses very accurate, which over time leads to a tighter and tighter data base. Unless you make logical misassumptions, in which case everything is up for grabs.

[twoshoes]

Judging from Joe Cardello\'s post on the form online Beyer made the number for the Belmont the same as he made the number for Bear Fan & Speightstown. The race wasn\'t nearly as slow as those earlier sprints would portend. They were being blown but good down the backside and the wind was in their puss in the stretch. They also evidently don\'t pay much attention to when and how moisture is being put down on the track. Another article that really serves as nothing more than an endorsment for your product TGJB.

[TGJB]

Yeah, I read that too. It made me want to ask him the same kind of question I asked LF at the Expo-- I\'m not asking you whether your Kee 2yo numbers are great (\"I guess we should give back the money we\'ve made betting\"). I\'m asking how you came up with the figure.

This should not be interpreted as a knock against Cardello overall-- his columns definitely are adding to the public\'s understanding of figures and their use. But this was the only 2 turn race on the card, with the track changing speed on the figures of anyone who is not a blind dogmatic, and I would love to hear how they decided on that figure. I started by giving RA a pair of his top, and that put the field about where you wanted them-- only the winner with a new top, SJ backing up some, the rest running off races. There\'s no way to claim this as a rock solid figure, but it feels about right, and all other scenarios felt much worse.