Here's a question for all you clever analytical types out there. The common assumption is that a selection rated as a 33% chance will win one race in three, all conditions being equal in each (repeated) race.

My question is this: is this assumption really true? Isn't the percentages we assign to a selection just a way of us estimating a selections chance, rather than reflecting what will happen in reality? Surely the same winner, in equal circumstances, will win again? Thus isn't the reality of any race really - winners chance:100% all others: 0% - rather than the market we frame for the race? Isn't the frame a way of adjusting for the unknown variables we can't predict?

I ask this because it is having a bearing on how I consider the viability and practical analysis of systems in general. Remember, stats is just a way of representing many numbers with just one "meaningful" one.

I'd be very interested to hear your considered opinions.

~Lenny

You can only say that the winner had 100% chance of winning the race AFTER the race. Before the race it had 33% chance (or whatever). If the same race with the same runners in the same conditions was run again it would then have a 100% chance of winning because, if all things are equal, it will win again. Which can't happen.

It is true than in *reality* the winner was going to win so in that sense it was a 100% thing, but the "chance" we ascribe to it is a human contrivance for human convenience, i.e. the chance is relative to the human ability to predict that it was going to win. What happened was never not going to happen, but human beings give themselves only a 33% chance of predicting it. So its the human ability to predict, not the reality of the outcome, to which the percentage refers. Or have I misunderstood you Lenny?

Hermes

On 2004-01-07 23:58, Lenny wrote:

Surely the same winner, in equal circumstances, will win again? Thus isn't the reality of any race really - winners chance:100% all others: 0%

No! Even if you put the same horses in the same barriers with the same conditions (track, wind, etc) you will not get exactly the same result. Horses (and jockeys) are not machines so they will not repeat the same performance twice.

If I take you to an indoor pool on 10 different days but with the same water temperature, etc, and get you to swim 100 metres will your time be exactly the same on all 10 occassions? Of course it wont - sometimes you will stuff up the start, sometimes your technique will be off, maybe you will mess up the turn, one day you will put it all together just right.

Exactly the same applies to a each horse in a race (and the jockey on its back). The "best" horse (the one we rate the best chance) will not always win for any number of reasons (bad start, blocked for a run, bad choice by the jockey, the horse is not running up to its best on the day or simply another runner puts it all together perfectly) but if you ran the race again any one of these could be different and the horse may win.

__________________
"Computers can do that????" - Homer Simpson

Hermes, I think you understood this situation perfectly. It is interesting that you ascribe the 33% chance not to the horse, but on the handicapper's ability to pick it! This is food for thought and I will indeed consider this idea further.

Becareful, well done! You picked up on a point I had hoped someone would have twigged onto. You said,

"...but if you ran the race again any one of these (conditions) could be different and the horse may win."

Rerunning becomes outside the parameters of this problem, as we want to consider the selections chances if the race was REPEATED, not rerun. In this case, I would say the winner is still likely to win again close to 100% of the time. The free will and choices of the contenders are likely to throw up different circumstances; but the chance of the winner winning again this time, in my opinion, is only a few percent off 100%. This, though, may vary depending on how clear his likely win is. The clearer the win, the closer to 100% of the time the rerunning winner will win again. Hard to get across, but a valid argument I think.

In short, there seems to be two bases (or philosophies) we all tend to bet by - finding the "definite" winner (direct approach) or finding the probable winner based on a statistical approach. I'm sure both approaches have their validity, but how they relate to each other is what interests me here.

Thanks guys,

~Lenny


[ This Message was edited by: Lenny on 2004-01-11 02:54 ]

WOW !!! Run all that by me again in layman's language would you ?

Cheers.

ECHO THAT SENTIMENT CRASH.

I think I see where you are going but I don't think there is a "lone winner" for a race. I believe that if you were able to repeat the race it is more than likely you would get a different winner.

For each race there are literally millions of different ways the race could be run, some result in horse A winning, some in horse B, some in Horse C, etc. When we are doing ratings we are trying to work out what the chance of a scenario where horse A winning occurs, the chance of a scenario where horse B winning occurs, etc.

If you were able to repeat the race you would get a different scenario as the chances of the race being run in EXACTLY the same way are millions to one - of course the different scenario may still give the same winner but that is where the probabilities come into it.

How many times have you watched a race and seen a runner lose the race because the jockey made the decision to try to go around the leaders but if he had waited a split second longer he would have seen the gap opening for an easy run through? Or a horse lose the race by missing the start? Or an outsider win because the leader went wide on the home bend taking 3 or 4 horses with it and giving the outsider the run through on the rail? If you repeated the race it is probable that these factors would change and therefore the race result would change.

__________________
"Computers can do that????" - Homer Simpson

[ This Message was edited by: puntz on 2004-01-31 00:32 ]

That is precisely why I bet on greyhounds and give the horses and trots a miss. Dogs are VERY VERY consistent. They are creatures of habit - a wide runner will always be a wide runner. A slow beginner will begin slowly 9 times out of ten. A railer will always look for the rails.
Therefore, times are everything in greyhound racing. As I said on another thread, I have been averaging a POT of 15% on the dogs for years now - to do that on the horses would take me probably three times the work and even then, you have the dreaded "bad ride" to contend with.

And of course, the dogs *NEVER* stop to scratch themselves either, do they????????

Or, they never get knocked for six by some mad railer in box 8 cutting them off...

Or, they never draw a middle box and get crunched from either side....

Or, they never get their legs knocked out from underneath them by some cat that runs up their backside....

Or.... there are just as many things that can go wrong in a dog race that there are in a thorougbred race, maybe even more.... And there's no protests either!