As you know I'm not much of a ratings guy. One of the issues I have with the various methods used to convert ratings to prices is their long term accuracy. For example do your Evens horses win 50% of the time? Do your 2/1 priced horses win one in three? etc etc.

My view is that ratings are of most use in ranking the selections, not pricing them

Though it may be an interesting discussion point.

__________________
Pixie

"It's worth remembering that profit isn't profit until it's spent off the racecourse." -- Crash

This is probably the best and most useful test a Rater could perform , but because I am frightened for some reason to do it with My Markets , I can't help at all.

I was almost to do it one time , but then I figured that supposing my animals weren't performing as they should? - what now?
I figure there would be errors in all brackets of animals.
the percentage error in each bracket should be identical.

Woof43 knows a little about this stuff.
Hopefully he notices this thread , and if he don't , I will alert him at my next opportunity.
The only problem is that he explain his thoughts so's other members can understand.
Although Angry Pixie , you seem a little better versed than most in WoofSpeak so you should be fine

Well thats the most innacurate and most misleading post I have ever posted.

I just realized that getting the animals to win in proportion to their assessed Chances is totally useless.
If your system did that , then you would be ending up with the General Publics Market.
The worthiness of a Ratings Market is in the profitability of the Overlays - NOTHING ELSE IS OF RELEVANCE.

You want them to win equal to or better than your assessed chances don't you?



Indeed. The overlay comes when your assessed chance differs to the positive from the chance arrived at by the market. To make a long term profit your assessed chance would therefore need to be more accurate than the market. This may be possible on select races but I doubt anybody has achieved this across all races.

__________________
Pixie

"It's worth remembering that profit isn't profit until it's spent off the racecourse." -- Crash

First of all you need to make sure your ratings/points have been compiled with a statistically valid method.

I have attached a sheet that shows how many points or weighting would be assigned for a Factor or each individual rank within a Factor.
I think I may have posted this a long time ago, it shows the weight of the Factor and the ROE just check the ROE +/- against your selected confidence level

Remember you need to measure your handicapping with Strike rate and Wagering with ROI.

The general public odds need to be converted to Natural Odds.

Your rated 20% chance indeed needs to win 20% of the time, this in itself is very hard to measure, as it is very rare that you will get a large enough sample of exactly 20% rated chances to test a small deviation makes a large difference.

Also your rated 20% chances if you had a large enough sample would win 20% of races right thru all the odds ranges. ie if I had 100 of these .20 chances and they started at even money i'd expect them to win 20 races with a normal variance.
hopefully this is understood.

Attached Files

zscore2l.xls (18.0 KB, 857 views)

Woof you could group them +/- 2.5%. It would be close enough to be indicative. Some of the long time ratings bod's would have plenty of past results at their disposal.

I guess I'm not suprised that this thread has had little interest. As moeee suggests it's probably a frightening prospect for many. Variance is nice when it's going your way

__________________
Pixie

"It's worth remembering that profit isn't profit until it's spent off the racecourse." -- Crash

Forums are like Radio Stations.
They attract people with different qualities.
It seems this Forum is for those that like to have fun.
Prospective Winners will have to look elsewhere.

It's all easy listening for me these days.

Another useful exercise would be to look at your top rated selections that went off under your price and therefore weren't bet. Are these winning more than your prices would suggest they should?

__________________
Pixie

"It's worth remembering that profit isn't profit until it's spent off the racecourse." -- Crash

Actually I have been trialling the use of a set of rated prices to find overlays that I plan to lay, testing so far has yielded around 1600 selections for a 95% lay strike rate with average winner (or loser in this case) around $9. I have been testing since December 2011 and will start live betting at the end of the month.

My thoughts were like most peoples in that overlays were the key to value and therefore profits when backing but I soon found that the market is a much better guide and I found that horses starting as "unders" had a better winning strike rate and lost less than those that would have been considered "overs" or value.

Of course not all overlays are bad value, I have introduced a few filters to maximise the layability of selections but it has made me re-think the notion of "always bet the value selections".

Cheers,

Mat.

Mattio
Interesting finding. About 6 mths testing. Is it all days, all venues. all goings?
Joe Public is reasonably good picking the toppies and as such these are usually the unders. They shun the potential also rans. These become the overs. You are using ratings to determine the overs, meaning that rating system has determined these horses better than what they actually prove to be. There are two types of overs, the first being the rated assessment of each of the horses compared with each other, and the second being the straight out numerical breakeven point. One is used when you are betting one race at a time and the other when betting en masse. The first is only an opinion. The second is useless if you are only betting an occassional race. What filters are you using? Beton