one quarter kelley

ScottH

Well-Known Member
#2
bnoc848 said:
whats the math formula for the one quarter kelley system?

thanks, bnoc
It's simple. Full Kelly is betting the same percent of your bankroll as your percent advantage. So if you have a 1% advantage you bet 1% of your bankroll on that hand.

Now to turn that into quarter kelly, when you have a 1% advantage you would bet 1/4% of your bankroll on the hand.
 

bnoc848

Active Member
#3
yea, but whats the math that i put into the calculator to get my 1/4 if my bankroll. Its pretty stupid but i forgot. and thx for the response
 

ScottH

Well-Known Member
#4
bnoc848 said:
yea, but whats the math that i put into the calculator to get my 1/4 if my bankroll. Its pretty stupid but i forgot. and thx for the response
You have to know what your advantage is at every TC. If you're using 1/4 kelly and your TC tells you that you have a 1% advantage, then you bet 1/4 of 1% of your bankroll, which is .25% of your bankroll.

To figure out how much .25% of your bankroll is, take your bankroll multiplied by .0025. OR you can take your bankroll times .01 and divide that number by 4 if that is easier for you.

One more example to make sure you get it. Assume you have a bankroll of 5000. Let's say you determined that you have a 3% advantage. To determine your bet using full kelly you take your bankroll (5000) times .03 which is 150. So 150 is your full kelly bet. Since you want to use 1/4 kelly you take 150 and divide it by 4, which would give you a bet of 37.50 at an advantage of 3%.
 
#5
ScottH said:
It's simple. Full Kelly is betting the same percent of your bankroll as your percent advantage. So if you have a 1% advantage you bet 1% of your bankroll on that hand.
For BJ full kelly is .75% of your advantage, to allow for splits/doubles. For 1/4 K I would just round to .20%. I think BNOC is trying to calc his bets based on "replenishable BR". zg

Ps - this forum is for NON-COUNTING-RELATED systems.
 

bnoc848

Active Member
#6
yea im using a replenishable br, and i thought it was the apropriate place to post this because its betting strategy and kelly betting is a betting startagey?
 

ScottH

Well-Known Member
#7
bnoc848 said:
yea im using a replenishable br, and i thought it was the apropriate place to post this because its betting strategy and kelly betting is a betting startagey?
This is what this section is for. "Discuss betting strategies other than card counting." The key words are "other than card counting". Kelly betting is a card counting related betting strategy.

This forum is for betting strategies that dont use card counting, such as progressions.
 

Sonny

Well-Known Member
#8
ScottH said:
Full Kelly is betting the same percent of your bankroll as your percent advantage. So if you have a 1% advantage you bet 1% of your bankroll on that hand.
Don't forget about the variance! :eek: It should be (Bankroll * EV) / Var. The variance is usually around 1.34 units at most counts. With a 3% advantage and a $5k bankroll the correct "Kelly" bet would be closer to $112, not $150. For Quarter-Kelly that would be about $28.

Although technically you are right. That has always been a big gripe of mine. :flame: The real formula for Kelly betting was not designed to work for BJ (or gambling at all, although the original paper did use a horse racing analogy) so we have to "tweak" it quite a bit in order to make it work. In my opinion we should give the formula above a new name since it is not the same formula as "true" Kelly (which Scott correctly stated as Bankroll * EV).

-Sonny-
 
#9
Sonny said:
Don't forget about the variance! :eek: It should be (Bankroll * EV) / Var. The variance is usually around 1.34 units at most counts. With a 3% advantage and a $5k bankroll the correct "Kelly" bet would be closer to $112, not $150. For Quarter-Kelly that would be about $28.

Although technically you are right. That has always been a big gripe of mine. :flame: The real formula for Kelly betting was not designed to work for BJ (or gambling at all, although the original paper did use a horse racing analogy) so we have to "tweak" it quite a bit in order to make it work. In my opinion we should give the formula above a new name since it is not the same formula as "true" Kelly (which Scott correctly stated as Bankroll * EV).
Lets call it "BJKelly" (sounds like a hooker I know) or BJK. 1/4BJK, etc. zg
 

Sonny

Well-Known Member
#10
ScottH said:
This forum is for betting strategies that dont use card counting, such as progressions.
I never noticed that before! I should read those descriptions more carefully. I always assumed this forum was for legit strategies. I guess that explains why there are so many progressions posts on here. :rolleyes: It seems strange that we would have a section for that since we spend so much time trying to discourage those sort of reckless betting habbits.

-Sonny-
 
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