Kelly Stake - Back Only

The Kelly Criterion is a staking method well known across wagering and investment professionals which should be known and considered by all Betfair punters.

Great explanation here:

 

 

Stake = f x Bank

f = fraction or % to bet

 

f = ((decimalodds-1)*p - (1-p))/(decimalodds-1))

 

Above is x100% and divisor ie divisor 2 = 0.5)

 

p = probability of winning ie 25% or 0.25

 

 

Starting bank = 1000, decimal odds 5, p = 25%

 

f = ((5-1)*0.25 - (1-0.25))/(5-1)

 

f= (1- 0.75)/4 = 0.25/4 = 0.0625 x 100% = 6.25%

 

f=((5x0.25 - 1) /(5-1))100

 

f= 0.25/4 x 100

 

f= 6.2%

 

Stake = 6.25% x 1000 = 62.5

 

1/2 kelly = divisor = 2 = 31.25

 

1/4 kelly = divisor = 4 = 15.63

 

if % negative = no bet