Acceptable risk of ruin

Morphy

Well-Known Member
#1
What is an acceptable ror? For example do you want to be below 5% or is 10% common

And is it different if you are a part time player vs full time ?
 

Meistro

Well-Known Member
#2
Partly it depends on how large your bankroll is and how you define the term bankroll. A $100,000 bankroll should be protected more carefully than a $10,000 bankroll. If you use bankroll to mean your net worth, as many professional players do, then even 1% ror is too high. If you use the term bankroll to mean a small portion of your net worth then playing with 5% ROR would be reasonable. The greater the risk the greater the reward.
 

Meistro

Well-Known Member
#3
You can also decrease your ROR by having a plan to move down. So if you are playing a $10,000 bankroll and have a max bet of $100, then you could say if you drop 25 max bets and go down to $7500 then you will decrease your max bet to $75. And if you drop down to 5k then you set your max bet at $50. Having a plan to move down during a downswing can significantly decrease your ROR.
 

Ryemo

Well-Known Member
#4
The answer to this question is completely subjective. Depends on a number of things. Is your bankroll replenishable or not? Are you a recreational player or serious hobbyist? Or do you play full time? What do kind of risk are YOU willing to put your money at?

When I played recreationally, my goal was to keep my RoR below 5%. Now that I play closer to full time (blackjack is a major source of income for me now), I try to keep my RoR below 1%. If I can get it below .5%, then even better.
 

sagefr0g

Well-Known Member
#5
am i correct, in remembering that there is a 'upper limit' in the neighborhood of ROR = 13.5% or so when it comes to optimal kelly betting? such that exceeding that 'limit' it becomes as if one were over betting, thus ever insuring eventual ruin? or is my memory on that matter erroneous?
edit: ahh found a reference here: https://www.blackjackincolor.com/blackjackrisk4.htm :end edit

anyway, @Morphy, its nice imho, to have options regarding picking and choosing the degree of one's ROR. there can be degrees of dynamic decision making as alluded to by Meistro. such decision making options will affect profitability. and as Ryemo indicates ones own decisions, subjectivity plays a role. just me maybe, it's interesting, far as those decisions, that one can ask one's self certainty equivalent like questions. such as like, hmm i have a choice between some spectrum of ROR%'s (which is like for example 100 counters playing the same game the same way (but different instances) at some ROR X%, then one expects X number of those counters to go bust at some time over the long run), the question becoming, does one want to take the risk of being in that X number of counters who went bust if it's likely to make some given profit?
 
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Meistro

Well-Known Member
#6
Exceeding Kelly is counter productive for the purposes of bankroll growth. Kelly is basically the maximum limit on how much you should ever bet. Kelly for blackjack is advantage * bankroll * .75. So for example if you have a 10k bankroll, and a 1% advantage @ TC 3 you would wager $10000 * 1% * .75 or $75 at TC3. Advantage by true count is determined through simulation and depends on rules and number of decks.
 

sagefr0g

Well-Known Member
#7
just curious,

wondering if anyone can explain
how it is so, that: (For the mathematicians, these risk rates roughly correspond to full Kelly, two-thirds Kelly, one-half Kelly and one-quarter Kelly.) as described in the link: https://www.blackjackincolor.com/blackjackrisk4.htm

also i'm wondering, if say 13% ROR corresponding to full Kelly as described holds only for 'typical' games of blackjack, such that other types of games would have a tendency of risk rates corresponding to full Kelly being some other relatively consistent number. i guess the question being, is the ROR% correspondence to full Kelly dependent on the advantage a given game has?
 

Meistro

Well-Known Member
#8
AFAIK Kelly and for that matter half kelly ROR should be true of any series of even money (well blackjack payouts are not really even money but it is close enough) wagers with a quantifiable edge. But that is just my understanding I don't really have much background in mathematics so don't quote me on that.
 
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