Hi Joelance,

Not by class but I do break them into 5 prize money bands which is a similar thing I suppose. Not really any significant results there. NSW I do a bit better in the top 5% by prize money but worse in QLD. Victoria the second to highest band is best. Figures pretty much all over the place really.
KV

Thanks for posting those figures Kenny, just going on those raw figures seems like the 15 starters produced your best return overall, I would have guessed that the 8- 14 fields would have the best returns. You mentioned your strike rate was about 29%, are you able to work out the strike rate just for the 15 runner fields? As you say it would probably be lower but with a higher average dividend. Are your bets usually top 2 or 3 in favouritism or do they vary quite a bit?

Don't know how significant the figures are around the 15 races mark, as you can see below the number of 15 horse races is a fair bit less than the average for all fields.

Strike rates:
Qld 24.1% on 15 runners against 28.8% overall. (430 races out of 20,000)
WA 24.8% against 27.4% (455 races out of 8500)
Nsw 22.1% against 29.1%, (440 races out of 32,000)

I honestly don't think the 15 races being best is significant, more chance. I just ran Victoria and it returns 95.7% on 15 runners, strike rate 19.10% against 26.4% (730 races out of 25000).

Yes generally the selections are in the top three of favoritism, I have had a $20 winner or two but they are red letter days indeed.
By the way, if I bet winners I bet to a price and find that this cuts the bets by about 50%, cuts the strike rate by 5 to 8% and boosts the ROI by 7.5 to 11% (depending on the state). Doesn't give any more meaningful figures by field size though.

KV

Thanks for that KV, I guess it still comes down to getting value for your selections or at the very least a minimum acceptable price for your selections.

Hi Kenny,

How have you found ROO for various field sizes? I tend to stick to field sizes of 8 to 14 for this reason. The odds might balance out the books but ROO potential on bigger fields of 15 and up always worry me. It's a psychological thing obviously as far as your figures go, but 'feeling' uncomfortable psychologically does make me think it is having an impact on my selection process [handicapping] and my bet amounts.

You had me scratching my head for a minute there, ROO, we're going to need an acronym glossary soon.
I don't isolate races by field size when I bet so it never really occurs to me what the run of outs is on any particular field size. Maybe I'm having a longer ROO on those races but hopefully a 5 or 6 horse race will come up in the mean time and ease the pain.
If you run the strike rates through a ROO predictor (23%ish against 29%ish) that would give the likely run of outs on those races compared to the overall figure.
Funny, I just ran NSW figures again and I get a strike rate of 35.6% in 6 horse races (2,135 of them) and 25.4% in 12 horse races (3500 of them). Now there's one for the statistics guys. Why don't you get a strike rate twice as good with half as many horses. And how can we use this to our advantage? 14 Horse races 23.7% against 7 horse races 32.9% - same question.

KV

Good SR averages Kenny. Unless you are backing fairly short priced runners, your making reasonable doh-ray-me $$$

I think the reason for your smaller than [mathematically] expected ROO prediction for larger races based on your SR in 6 and 12 horse fields, is simply due to the fact that larger fields are loaded with more rubbish horses.

What mainly counts is the 3 or 4 real chances [on average] that make up 80% winning chance in a 12 horse race, compared to say 2 to 3 real chances making up 80% of winning chance in a 6 horse race. The number of winning chances are not halved in a 6 horse race compared to a 12 horse race.

If all horses had the same chance in both field sizes, you would find a bigger ROO potential for a 12 horse field and would get a smaller SR. Considering the real winning chances in an average 12 horse field, your SR of 24.9% should actually be better. The reason it isn't is that more possible unforeseen events happen [having to run wider, bumping and less opportunities to come through from behind etc.] in larger races. So in fact the SR% in larger races look OK, but my seasoning and explanations above suggest they are not as good value as they look on paper and point too larger races actually being poorer value if you follow my drift[?].

9 to 12 runners is my prime field size pick for odds and confidence ratio. Above 14 runners is my cut off for perceived value. The SR's you have mention seem to support this logic I think, but in the scheme of things as far as your concerned, I'd just keep doing whatever you are doing.