Quote:
Originally Posted by BarchCapper
Is this a case of the Brisnet chart being based on the toteboard odds (which include the track takeout), and Formula's calculations of fair payout being based on the true probabilities based on those odds after eliminating the takeout?
Example:
Win pool is $100,000
Takeout is 20%
Horse A has $20,000 wagered to win
Horse A toteboard odds: 3-1 ($80,000 left in pool after take-$20K bet on horse A=$60K/$20K bet on horse A=25% "tote" probability)
Horse A "true" odds: 4-1 ($100,000 total pool-$20K Horse A=$80K/$20K=20% "true" probability)
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from my web page
based on a 15% win pool take out
THE PROBABILITY OF A HORSE WINNING IS (1/(ODDS+1))/ THE RACES TOTAL BOOK PERCENTAGE .
THE TOTAL BOOK PERCENTAGE FOR A TRACK WITH A 15% TAKE OUT SUMS TO ABOUT 1.18
THE PROBABILITY OF ANY HORSE WINNING IS (1/(ODDS+1))/1.18
TAG THE WIN HORSES WIN PROBABILITY WITH "A"
TAG THE PLACE HORSE WIN PROBABILITY WITH "B"
EXACTA PROBABILITY PROBABILITY FOR A/B IS:
A X (B/(1-A))
EXAMPLE: A HORSE ODDS =2-1, B HORSE ODDS = 3-1, TRACK TAKE OUT IS 15%
A HORSE WIN PROBABILITY IS (1/(2+1))/1.18 = .282
B HORSE WIN PROBABILITY IS (1/(3+1)/1.18 = .212
PROBABILITY FOR THE A/B COMBINATION IS,
.282 x(.212/(1-.282)) = .083
THAT EQUATES TO A $1 RETURN OF (1/.083)= 12.04
THE FAIR $1 PAYOUT IS $12.04
