Exacta Part Wheel Proportional betting

[Ray2000]

I'm running a little study testing proportional betting on Exacta part wheel tickets and was wondering if anyone else structures their bets this way.

My Exacta wheel plays take the form of A/BC or A/BCD or even A/BCDE
This test assumes a constant risk of $36 per race either 18/18 or 12/12/12 or 9/9/9/9 depending on number of horses on bottom of the ticket.

I'm comparing the P/L to betting the bottom horses proportionally to their $2 probables.
(for this test I'm using final probables, in real time I'd have to use -2 MTP)
I'm gambling on the hope? that the pool inefficiencies will help as much as hurt on my plays.

So far I've tabulated 161 hits in November. (Shhh on the misses )
Of those, the flat return is $26,394....the proportional bet sizing return is $28,022
giving a increased return of 6.2%

The attachment shows 3 examples of this type of bets.
Total 3 race return of $521 vs $632
I picked good ones for the demo.

I didn't include the 3 Exacta Will-pay grids in the picture. too messy
I'll post the final test numbers later after a larger sample is available.

Any comments?

[SchagFactorToWin]

I'm unclear as to how you are calculating the betfrac figures.

Am I correct in thinking that the expected exacta pays are a stand-in for odds of winning? So that bet sizes will be proportional to the payouts, i.e. you'll be betting bigger on the lower expected pays?

[Ray2000]

Good to see your posts Schag, you're correct with the largest bet goes on the smallest payoff.

Here's an example that hurt me last night, (trying to watch the Steelers and the board at the same time )

 Yonkers Race 10  2$ Exacta Probs at last chance to bet.
	1	2	3	4	5	6	7

1	 	62	273	100	179	194	621
2	18	 	50	12	26	28	123
3	317	161	 	219	471	232	817
4	36	10	80	 	54	41	174
5	140	50	241	89	 	133	542
6	100	37	155	57	112	 	242
7	737	305	993	494	941	438	

Converting this grid to the probabilities of each possible outcome using the formula in OP
Assumes the pool is perfectly efficient, ignores breakage.


	1	2	3	4	5	6	7

1		0.028	0.006	0.017	0.009	0.008	0.003
2	0.114		0.035	0.200	0.073	0.067	0.013
3	0.005	0.010		0.007	0.003	0.007	0.002
4	0.050	0.267	0.021		0.032	0.043	0.009
5	0.012	0.035	0.007	0.019		0.012	0.003
6	0.017	0.048	0.011	0.030	0.015		0.007
7	0.002	0.005	0.002	0.003	0.002	0.004

My bet last night was a $12 Exacta 2/1,3,6 ($36)

so the numbers I'm interested in are the red ones the probs of 2-1, 2-3, 2-6
0.114 + 0.035 + 0.067 adds up to 0.216

and the fractions are 114/216 , 35/216 , 67/216
breaking the $36 down to,... $19 on the 2-1, $6 on the 2-3, and $11 on the 2-6

This time I got stung bad on 2-3 paying $49.80
Straight betting would return $299 Proportional returns $149

but so far the balance is in favor of betting different amounts on the underneath horses.

Best of Luck