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 :D )
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