risk of ruin

EasyRhino

Well-Known Member
#2
A true fixed bankroll means that you will never, ever, ever, be able to replenish it. If you lose it, you're at, best, out of the game forever, and and worst, you're living on the streets, because your bankroll is what you used for food and rent.

If you start with a full Kelly fraction (for optimal bankroll growth), but never resize bets, you have a 13.5% risk of ruin. Most people are more careful than this if the bankrolls are sizeable.
 

Kasi

Well-Known Member
#3
mjbballar23 said:
can someone tell me what is an acceptable risk of ruin to play with if i have a fixed bankroll?
Who knows.

If you're talking Kelly fractions, maybe 1/8. Maybe less.

ROR is one thing but chances of losing x percent of roll at some point is another.

Not to mention maybe factor in all the things that can make you lose more.

I mean 13.5% might not sound that bad but do you really want to take a 10% of losing 90% of your bankroll at some point?

Anyway, I'd be interested in hearing what fraction, if any, any counting teams may have used with their large rolls.

Or how anybody might go about it.
 

mdlbj

Well-Known Member
#4
EasyRhino said:
A true fixed bankroll means that you will never, ever, ever, be able to replenish it. If you lose it, you're at, best, out of the game forever, and and worst, you're living on the streets, because your bankroll is what you used for food and rent.

If you start with a full Kelly fraction (for optimal bankroll growth), but never resize bets, you have a 13.5% risk of ruin. Most people are more careful than this if the bankrolls are sizeable.
Only to add to what Easy has posted... This is only if you play absolutly perfectly.
 

SystemsTrader

Well-Known Member
#5
mjbballar23 said:
can someone tell me what is an acceptable risk of ruin to play with if i have a fixed bankroll?
Well unfortunately there is no perfect number here. Risk really comes down to what the individual is comfortable with. However you also must be reasonable here. Playing with anything over a full kelly will almost guarantee failure. For myself I like to play with a ror between 2% and 5% at most and I prefer to be at the lower end of the scale. The size of your bankroll will also determine how much risk you must take. The smaller the bankroll the larger the risk you will have to take! Then there is the other side to consider as well such as how fast do you want to double your account. While a low risk might be safer it might not make it worth your time to play if you aren't making enough money. You will have to find a happy median which suits your comfort level. Sorry I can't be specific for you.
 
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Paradox

Well-Known Member
#6
I use a 1/10 KEB to my net worth

Depends on your tolerance. Full Kelly is suicide, half kelly is still somewhat aggressive to me.
 

Dopple

Well-Known Member
#7
So if a guy went to Wendover he could play start with a 1000 bankroll and play one red less than the tc and be within reasonable risk could he not?

It would be all min 5 bets until the count rose walking quite often on negative counts when playing a shoe.
 

EasyRhino

Well-Known Member
#8
I don't know if you'd find any shoes in wendover, but if I read that right, in a TC of +5, you'd have (very very approximately) a 2% advantage, and you'd be betting $20 from your $1000 bankroll.

This would sort of kind of approximate fully kelly betting, so if you played infinitely you'd have the 13% chance of losing all $1000, and larger chances of losing a big chunk of the bankroll. But if it was a short trip, the risk of ruin would be smaller.
 

Cardcounter

Well-Known Member
#10
Risk of Ruin?

The risk of ruin is directly related to weather or not you are a good enough player to get an advantage. If you are not good enough to get an advantage your risk of ruin is 100% no matter what your bankroll it is just a matter of time. If you can get a advantage than all you need is a bankroll to make the risk of ruin 0 if you have a million unit bank roll than your risk of ruin is 0. The risk of ruin that I generally think of is my playing session bankroll. Because my total buyins total more and more everyday. Lets take your playing bankroll of 40 units and you plan to play for 150 hands of action. Than you would have a considerable risk of losing your playing session bankroll.
 

Kasi

Well-Known Member
#11
EasyRhino said:
you'd have (very very approximately) a 2% advantage, and you'd be betting $20 from your $1000 bankroll.
Assuming you did have a 2% advantage and $1000 roll, don't forget to divide by the variance in determing a Kelly bet. So it'd be more like $15.

But, more important, is the the overall betting scheme and what risk that has since you can't always make a called-for Kelly bet.
 

Kasi

Well-Known Member
#12
Cardcounter said:
Lets take your playing bankroll of 40 units and you plan to play for 150 hands of action. Than you would have a considerable risk of losing your playing session bankroll.
I guess you're bringing up "session bankroll" vs "trip bankroll" vs "lifetime bankroll".

How do you evaluate that the risk is "considerable" in the above scenario?
 

Kasi

Well-Known Member
#13
Dopple said:
So if a guy went to Wendover he could play start with a 1000 bankroll and play one red less than the tc and be within reasonable risk could he not?

It would be all min 5 bets until the count rose walking quite often on negative counts when playing a shoe.

How do you expect anyone to answer that lol?

It greatly depends on the game in question and how you play it (how often do you walk on negative counts, etc), how the $1000 relates to a trip or lifetime bankroll, etc.

If you really want to know think about buying a sim.

But, you know, even a BS player can't lose 200 units in a day or 2 lol.
 
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