vpFREE2 Forums

kelly bankroll for JoB

ok, so on second glance, it's actually closer to reasonable than i thought.
risk of ruin is a silly metric to be using here, since most of us aren't
locked into a single game forever and ever, we'll move up or down as our
bankroll grows or shrinks.

a more useful figure is kelly-optimal bankroll sizing, figuring out what
stakes will maximize long-term bankroll growth. if we have two games with
winrates x1 and x2, and standard deviations y1 and y2, then we maximize
log-utility by switching from the smaller game 2 to the larger game 1 at
bankroll size (y1^2 - y2^2) / 2*(x1 - x2).

using this formula we get the following thresholds for JoB:

         0.25->1 1->2 2->5 5->10 10->25
0.75% 21k 50k 116k 249k 581k
1.00% 11k 27k 63k 135k 314k
1.25% 8k 18k 43k 92k 215k
1.50% 6k 14k 33k 70k 164k

so it's actually kelly-optimal to switch from quarters to dollars on JoB
with 0.75% cashback at a bankroll size of 21k, not too much higher than the
$17500 that someone mentioned. of course the moment you dip below 21k, it's
then appropriate to switch back to quarters, and most people don't want to
do that, so they'd be better off waiting a little longer to move up.

and the usual caveats with kelly analysis apply. for one thing, this all
assumes no errors, no tips, no expenses, never spending any money out of
bankroll, etc, etc. most of us should allocate at least 0.1% for errors and
tips, reducing the nominal cashback accordingly. for another thing,
full-kelly betting involves much wilder bankroll fluctuations than most
people are willing to stomach.

(also, the formula i gave assumes a normally distributed range of results,
which is decidedly not the case for video poker. but it should be close, and
i am not bored enough to compute the exact numbers right now. seemed
interesting enough to post as it is.)

cheers,

five

[Non-text portions of this message have been removed]

···

On Dec 19, 2007 4:06 PM, fivespot <fivespot55@gmail.com> wrote:

for the $17500 you suggest, X=3500, and RoR is about 30.1% [...]
i still wouldn't play $1 JoB with 0.75% cb on a $17500 bankroll. :slight_smile:

A similar quick calculation: If Bob's got a bankroll of 2 million, his
Kelly optimal bet (approximate) at 9/6 JOB with .75% cashback is:
$2 million x (-.005+.0075)/20 = $250. Of course, this ignores his
other bet, the stock fund his bankroll is sitting in currently, but
the 50dmA is probably negative on that anyway. A different comparison
would result with a fixed return fund. That would be the Sharpe ratio.

> for the $17500 you suggest, X=3500, and RoR is about 30.1% [...]
> i still wouldn't play $1 JoB with 0.75% cb on a $17500 bankroll. :slight_smile:

ok, so on second glance, it's actually closer to reasonable than i

thought.

risk of ruin is a silly metric to be using here, since most of us aren't
locked into a single game forever and ever, we'll move up or down as our
bankroll grows or shrinks.

a more useful figure is kelly-optimal bankroll sizing, figuring out what
stakes will maximize long-term bankroll growth. if we have two games

with

winrates x1 and x2, and standard deviations y1 and y2, then we maximize
log-utility by switching from the smaller game 2 to the larger game 1 at
bankroll size (y1^2 - y2^2) / 2*(x1 - x2).

using this formula we get the following thresholds for JoB:

         0.25->1 1->2 2->5 5->10 10->25
0.75% 21k 50k 116k 249k 581k
1.00% 11k 27k 63k 135k 314k
1.25% 8k 18k 43k 92k 215k
1.50% 6k 14k 33k 70k 164k

so it's actually kelly-optimal to switch from quarters to dollars on JoB
with 0.75% cashback at a bankroll size of 21k, not too much higher

than the

$17500 that someone mentioned. of course the moment you dip below

21k, it's

then appropriate to switch back to quarters, and most people don't

want to

do that, so they'd be better off waiting a little longer to move up.

and the usual caveats with kelly analysis apply. for one thing, this all
assumes no errors, no tips, no expenses, never spending any money out of
bankroll, etc, etc. most of us should allocate at least 0.1% for

errors and

tips, reducing the nominal cashback accordingly. for another thing,
full-kelly betting involves much wilder bankroll fluctuations than most
people are willing to stomach.

(also, the formula i gave assumes a normally distributed range of

results,

which is decidedly not the case for video poker. but it should be

close, and

···

--- In vpFREE@yahoogroups.com, fivespot <fivespot55@...> wrote:

On Dec 19, 2007 4:06 PM, fivespot <fivespot55@...> wrote:
i am not bored enough to compute the exact numbers right now. seemed
interesting enough to post as it is.)

cheers,

five

[Non-text portions of this message have been removed]

i dunno, that'd be the right figure if he were flipping coins with a
0.25%edge, and i know you said this is just an approximation, but i
think it's a
little much to entirely neglect the variance level of the game.

for example optimal bet size is going to be different if your 0.25% edge is
at super aces than if it's at jacks - at jacks you switch from $10 to $25 at
a bankroll size of $672k, whereas at super aces you stay with $10 until
you're over $2.2M. big difference.

cheers,

five

[Non-text portions of this message have been removed]

···

<nightoftheiguana2000@yahoo.com> wrote:

A similar quick calculation: If Bob's got a bankroll of 2 million, his
Kelly optimal bet (approximate) at 9/6 JOB with .75% cashback is:
$2 million x (-.005+.0075)/20 = $250.

The variance is in there, estimated at 20.
Kelly Bet = Bankroll x edge/variance

<nightoftheiguana2000@...> wrote:

> A similar quick calculation: If Bob's got a bankroll of 2 million, his
> Kelly optimal bet (approximate) at 9/6 JOB with .75% cashback is:
> $2 million x (-.005+.0075)/20 = $250.

i dunno, that'd be the right figure if he were flipping coins with a
0.25%edge, and i know you said this is just an approximation, but i
think it's a
little much to entirely neglect the variance level of the game.

for example optimal bet size is going to be different if your 0.25%

edge is

at super aces than if it's at jacks - at jacks you switch from $10

to $25 at

···

--- In vpFREE@yahoogroups.com, fivespot <fivespot55@...> wrote:

a bankroll size of $672k, whereas at super aces you stay with $10 until
you're over $2.2M. big difference.

cheers,

five

[Non-text portions of this message have been removed]

Five, your approximation using the normal distribution is pretty
good, but the figs do come out a little low. I'm being lazy, too,
so I went to jazbo's site for a quick comparison.

http://www.jazbo.com/videopoker/kelly.html

jazbo has the Kelly bankroll for 9/6 $1 JOB with 1% cashback as
$14,585. You have $11,000 in your quick calc table. jazbo is doing
the full calculation (maximizing log growth based on the payoffs and
frequencies)

--Dunbar

> for the $17500 you suggest, X=3500, and RoR is about 30.1% [...]
> i still wouldn't play $1 JoB with 0.75% cb on a $17500

bankroll. :slight_smile:

ok, so on second glance, it's actually closer to reasonable than i

thought.

risk of ruin is a silly metric to be using here, since most of us

aren't

locked into a single game forever and ever, we'll move up or down

as our

bankroll grows or shrinks.

a more useful figure is kelly-optimal bankroll sizing, figuring

out what

stakes will maximize long-term bankroll growth. if we have two

games with

winrates x1 and x2, and standard deviations y1 and y2, then we

maximize

log-utility by switching from the smaller game 2 to the larger

game 1 at

bankroll size (y1^2 - y2^2) / 2*(x1 - x2).

using this formula we get the following thresholds for JoB:

         0.25->1 1->2 2->5 5->10 10->25
0.75% 21k 50k 116k 249k 581k
1.00% 11k 27k 63k 135k 314k
1.25% 8k 18k 43k 92k 215k
1.50% 6k 14k 33k 70k 164k

so it's actually kelly-optimal to switch from quarters to dollars

on JoB

with 0.75% cashback at a bankroll size of 21k, not too much higher

than the

$17500 that someone mentioned. of course the moment you dip below

21k, it's

then appropriate to switch back to quarters, and most people don't

want to

do that, so they'd be better off waiting a little longer to move

up.

and the usual caveats with kelly analysis apply. for one thing,

this all

assumes no errors, no tips, no expenses, never spending any money

out of

bankroll, etc, etc. most of us should allocate at least 0.1% for

errors and

tips, reducing the nominal cashback accordingly. for another thing,
full-kelly betting involves much wilder bankroll fluctuations than

most

people are willing to stomach.

(also, the formula i gave assumes a normally distributed range of

results,

which is decidedly not the case for video poker. but it should be

close, and

i am not bored enough to compute the exact numbers right now.

seemed

···

--- In vpFREE@yahoogroups.com, fivespot <fivespot55@...> wrote:

On Dec 19, 2007 4:06 PM, fivespot <fivespot55@...> wrote:
interesting enough to post as it is.)

cheers,

five

[Non-text portions of this message have been removed]

I do not want to start an argument. I just want to state my own personal counter OPINION.
What is good for YOU, is great and I am not speaking against that.

However, for me, any long-term calculation is meaningless. I want to know what I will need
for any several day visit to some gambling venue. That way I can gamble to my heart's
content, without worrying about running out of money. For my next visit, I can do the "short
term" calculation over again, with respect to what I am planing to do, in terms of a specific
game (or games) and denominations.

..... bl

···

--- In vpFREE@yahoogroups.com, fivespot <fivespot55@...> wrote:

risk of ruin is a silly metric to be using here, since most of us aren't
locked into a single game forever and ever, we'll move up or down as our
bankroll grows or shrinks.

>
> risk of ruin is a silly metric to be using here, since most of us

aren't

> locked into a single game forever and ever, we'll move up or down

as our

> bankroll grows or shrinks.
>

The Commando's rule-of-thumb Risk of Ruin appraisal: If the play bores
you to tears you are definitely playing within the means of your
bankroll. Conversely, if the play is very exciting to you, you are
definitely overplaying your bankroll. Good luck.

···

--- In vpFREE@yahoogroups.com, fivespot <fivespot55@> wrote:

--- >

The Commando's rule-of-thumb Risk of Ruin appraisal: If the play

bores

you to tears you are definitely playing within the means of your
bankroll. Conversely, if the play is very exciting to you, you are
definitely overplaying your bankroll. Good luck.

perfect example
I find that 25c pic-em bores me to tears. My blood gets pumping at
$1. 50c is just about rite. Unfortunately, not too easy to find,
especially in QC, Ia. Good ole Dubuque gas it, but too far away to go
to much, & no CB.

Merry xmas & happy holidays to all for one of the best things I've evr
discovered on internet.

···

--- >

The Commando's rule-of-thumb Risk of Ruin appraisal: If the play

bores

you to tears you are definitely playing within the means of your
bankroll. Conversely, if the play is very exciting to you, you are
definitely overplaying your bankroll. Good luck.

perfect example
I find that 25c pic-em bores me to tears. My blood gets pumping at
$1. 50c is just about rite. Unfortunately, not too easy to find,
especially in QC, Ia. Good ole Dubuque gas it, but too far away to go
to much, & no CB.

Merry xmas & happy holidays to all for one of the best things I've evr
discovered on internet.

···

fivespot wrote:

risk of ruin is a silly metric to be using here, since most
of us aren't locked into a single game forever and ever, we'll move
up or down as our bankroll grows or shrinks.

a more useful figure is kelly-optimal bankroll sizing, figuring out
what stakes will maximize long-term bankroll growth.

Similar to bl, I'll offer my take.

It's reasonable to say that most casual players manage their bankroll
session to session -- allow for a loss based upon resources at hand,
fully expecting that over time they'll replenish any drain due to loss
from future income. If one wanted to quantify their bankroll, Jean
Scott suggests that it would be measured by the aggregate loss their
willing to absorb over a given period of time before quitting the game
(possibly restarting once they've come to terms with that loss and are
prepared to continue allocating/risking future earnings.

However, I'll suggest that the prudent player has a predetermined loss
tolerance in mind -- whether funded from existing reserves, or to be
funded on a "play as you go" basis. It's the best means by which to
avoid (or minimize) "gambler's regret" -- the sinking feeling one is
vulnerable to in sensing that one foolishly made play decisions that
resulted in ruin (and, in hindsight, in the heat of the moment
absorbed more than acceptable losses).

The consequence is that in one form or another, most players operate
under a reasonably well defined bankroll constraint. Whether they
manage their play according to it is another matter. But some
measurement of their play against bankroll risk is very desirable.

···

------

The notion that a player will simply manage their bankroll by
adjusting denomination as necessary is simplistic. Unlike many table
games, the betting increments available in video poker are dramatic,
where betting must often be doubled or halved to effect an adjustment.
This can be further exaggerated when play is restricted to strong
games and those games are available in very limited denoms (e.g. $1
and $.25 only).

The consequences of a downward shift in vp denom can't be easily
dismissed either. For most recreational players, the comps aspect of
play is a critical source of play satisfaction. A cut in play
denomination will likely mean a sharply reduced daily coin in and a
sizable cut in benefits extended by the casino.

The benefit factor is one that likely induces many players to overplay
their bankroll, being hesitant to downsize and hoping that luck plays
in their favor in the near term and restores them to a comfortable
bankroll. With short term prospects negatively skewed, I'd anticipate
that this often ends very disappointingly -- with many walking from
the game rather than pushing on at a lower denom.

------

All this said, most active players intuitively do manage their play
according to a reasonable perception of risk. The play a small number
of paytables and in fairly short order find the denomination for which
the implicit swings are most comfortable and yet generate sufficient
excitement. Resorting to statistical ROR calculators and formulae are
hardly necessary.

But most players encounter infrequent occasions where there's a
temptation to stray into unfamiliar turf, where they don't have the
necessary experience from which to have a reasonable intuitive sense
of risk.

These might include unique opportunities -- a juicy progressive with a
reduced base paytable or a casino promotion for which the optimal
machines involve a denomination jump, for example. It's difficult to
make an off-the-cuff call whether this reward/risk tradeoff is
consistent with their current bankroll limitation.

I assert in these cases is player is best positioned if they can
assess exactly how the risk of these plays compared with the risks
that they regularly take on in the existing play. At the very least,
forewarned with this information, they can make a more intelligent
play decision and will more likely be prepared to accept the
consequences, if adverse, without remorse.

------

Another play dimension worth considering is the temptation to take
"pot shots" with one's bankroll. Many players will temporarily jump
to a more risky play or jump denomination in hope of a quick hit. A
stronger familiarity with the risk of ruin concept, and how their
bankroll measures up against their current play, will mean more
rational decisions when it comes to pot shots.

There's a definite irrationality that often comes into play with pot
shots. A player enjoys a very good run of luck and reasons that they
can afford to risk a little of it on a riskier, but high paying play.
What's missing is a recognition that such good runs are to be
expected and are a necessary component of sustaining a play --
offsetting the equally expected dry spells. To risk funds on a play
that isn't sustainable in the long run is to accept a permanent
bankroll drain if not successful -- you can't expect that, in the
course of things, the regular play will replenish the losses.

An example is a $.25 player who steps up to $.50 or $1 play
occasionally (or a $1 player taking a shot at $2). It's only
reasonable that is very unlikely that a loss taken on $.50 play will
be offset by a good run at half that denomination.

------

All of the preceding is to argue that ROR is a very tangible and
pertinent concept to active players who put serious money at risk.
There are software calculators that readily calculate ROR from various
sources (VP for Winners, includes one, for example; free ones are on
the internet as well), so getting hard numbers is not a hurdle for the
casual player.

It's some of the practical considerations that require a little
education to best understand how to apply ROR to play decisions
(including what thresholds to set and the understanding that most
players want to measure against the specific bankroll limitation that
would lead the player to make a concrete change in their play, rather
than against total bankroll resources).

------

With respect to kelly bankroll numbers -- While Kelly has some limited
useful application to vp, in general I find it wholly unsuited.

Kelly optimizes bankroll growth, yet I don't think that's an apt goal
for a casual player. If you're standing in an 30th floor office in a
building and I tell you that the quickest way to the sidewalk is to
walk out the window, that hardly suggests that's a prudent action.

That's an extreme analogy, but it's meant simply to suggest that kelly
risk is generally higher than a casual player is comfortable with.

Further, Kelly is best applied to games such as blackjack, where the
increment in betting options is relatively small. It's very easy to
make betting adjustments as bankroll shifts (of course, it's to be
noted that a player thinking in Kelly terms is unlikely to be making
minimum table bets on average). VP allows very limited discretion in
adjusting wager.

- Harry

With respect to kelly bankroll numbers -- While Kelly has some limited
useful application to vp, in general I find it wholly unsuited.

I dunno ... wholly unsuited?

Kelly optimizes bankroll growth, yet I don't think that's an apt goal
for a casual player. If you're standing in an 30th floor office in a
building and I tell you that the quickest way to the sidewalk is to
walk out the window, that hardly suggests that's a prudent action.

That's an extreme analogy, but it's meant simply to suggest that kelly
risk is generally higher than a casual player is comfortable with.

Makes sense, of course it's widely held, for example in finance, that
one should back down from the extreme Kelly edge. That one should
trade off some capital preservation (reduced risk) in exchange for
reduced growth (less reward). Kelly is just a tool, a tool among many,
not a manifesto.

Further, Kelly is best applied to games such as blackjack, where the
increment in betting options is relatively small. It's very easy to
make betting adjustments as bankroll shifts (of course, it's to be
noted that a player thinking in Kelly terms is unlikely to be making
minimum table bets on average). VP allows very limited discretion in
adjusting wager.

The times they are a changing. 10 coin and more machines are appearing
on the landscape, where 5 coins and up is full pay, allowing bets of 5
or 6 or 7 etc. coins. True, you can rarely make an exact Kelly bet,
but the same is true of table games. Nevertheless, Kelly is a tool and
can still be applied by those who so choose. For example, it can tell
you when you should back down from $5 games to $1 games and from $1
games to quarter games, when you should play like Bob Dancer, etc.
Most gamblers would of course ignore the mathematical advice, but what
else is new under the sun?

···

--- In vpFREE@yahoogroups.com, "Harry Porter" <harry.porter@...> wrote:

I guess I should make an example. Let's say your choice of games is
nickel, quarter or fidy-cents five-coin full pay deuces, dollar NSU
5-10 coin with 3/4% card club, $5, $10 or $25 JOB with 1% card club.
Kelly can be used to tell you which game to play based on your
bankroll, assuming your goal is to maximize your bankroll growth.
Kelly can also tell you when to change games, as your bankroll grows
or shrinks. Oh hey, you spotted a new game or a progressive? Kelly can
tell you where it fits in. EV is not everything.

Five, your approximation using the normal distribution is pretty
good, but the figs do come out a little low. I'm being lazy, too,
so I went to jazbo's site for a quick comparison.

http://www.jazbo.com/videopoker/kelly.html

ha, how did i forget about that page :slight_smile:

jazbo has the Kelly bankroll for 9/6 $1 JOB with 1% cashback as

$14,585. You have $11,000 in your quick calc table.

actually the main reason why my figure is lower is that i'm computing the
bankroll at which it is better to play $1 than $0.25, rather than the
bankroll at which a $1 game is optimal. at say $13000, dollars is too big
and quarters is too small, but dollars offers greater expected log-utility
gain than quarters if those are your two choices. if there's a $0.50 game,
you'd play that instead.

actually, it looks like using the normal distribution overestimates bankroll
requirements, not underestimates. if i use that formula from my last post to
calculate the threshold at which you move up from $0.99 to $1, it spits out
$17846, which suggests that it thinks the optimal kelly bankroll for $1 is
slightly more than that. this is over 20% higher than jazbo's figure using
the actual distribution.

to summarize that last paragraph: it turns out to be less risky to play a
game with limited downside than a game with unlimited downside! now there's
a shocker :slight_smile:

i computed the exact kelly requirements myself and came up with slightly
different numbers than jazbo (for example $14860 instead of $14585 for $1
jacks with 1% cashback), but close enough that it doesn't concern me.

cheers,

five

[Non-text portions of this message have been removed]

···

On Dec 20, 2007 6:22 PM, dunbar_dra <h_dunbar@hotmail.com> wrote:

does it really count as a "counter opinion" if we don't actually disagree?
:slight_smile:

short term bankroll calculations are useful. i use them too, for instance to
determine how much money i'm likely to need on a trip, since i don't use
credit.

i made a negative comment about the usefulness of computing long-term risk
of ruin, which is very different. it seems to me that a player who's
concerned about long-term statistics would usually be better off with kelly
analysis. since you're unconcerned with long-term statistics, you can
obviously ignore both. :slight_smile:

cheers,

five

[Non-text portions of this message have been removed]

···

bornloser1537 <bornloser1537@yahoo.com> wrote:

I do not want to start an argument. I just want to state my own personal
counter OPINION.
What is good for YOU, is great and I am not speaking against that.

However, for me, any long-term calculation is meaningless. I want to know
what I will need
for any several day visit to some gambling venue.

harry, you make a lot of good points, and maybe some players (even smart
players) are more locked into a single game/denom than i'd expect and
actually have use for long-term RoR figures.
but i'm curious about this, mostly unrelated to the RoR issue:

The consequence is that in one form or another, most players operate
under a reasonably well defined bankroll constraint.

...really?

i played video poker for the first time about a year ago. the game was worth
about $150/hr, and a friend and i beat it for about $10k before getting
kicked out. if "bankroll" is the amount you're willing to lose before you
quit, i have no idea what my bankroll was at the time. i would have found
losing $5k painful, and i knew there was a high probability of pain given
the stakes. would i have persisted through an initial loss of $5k? or $10k?
or $20k? dunno.

i have a slightly better idea now, having lost $20k+ at times and learned
how i react to it, but i've still used figures varying by a factor of four
for my hypothetical bankroll depending more on how i'm feeling that day than
on any objective change of circumstance.

most gamblers i know in person have similarly vague notions of what their
bankroll is, beyond "i'm not going to lose everything in the bank". in
practice what would make them quit is a succession of punches to the stomach
that added up to intolerable pain, only loosely correlated to financial
impact. in other words, the very antithesis of "well defined".

so now i'm curious how many people here think their bankroll is "well
defined".

cheers,

five

[Non-text portions of this message have been removed]

···

Harry Porter <harry.porter@verizon.net> wrote:

so now i'm curious how many people here think their bankroll is "well
defined".

cheers,

five

I've always struggled with it. Just the fact that in the time that it
takes to lose one's current "bankroll," there will likely have been
other expenses and income, which may not be easy to estimate,
particularly since it's also uncertain how long losing it will take,
makes it hard to define. The Kelly Criterion assumes a much more
"closed system" than gamblers normally face and I've just about always
gotten squeamish long before I've gotten up to the bet amount that it
would suggest based on what I thought was my bankroll, so I tend to
ignore it.

> Five, your approximation using the normal distribution is pretty
> good, but the figs do come out a little low. I'm being lazy,

too,

> so I went to jazbo's site for a quick comparison.
>
> http://www.jazbo.com/videopoker/kelly.html

ha, how did i forget about that page :slight_smile:

jazbo has the Kelly bankroll for 9/6 $1 JOB with 1% cashback as
> $14,585. You have $11,000 in your quick calc table.

actually the main reason why my figure is lower is that i'm

computing the

bankroll at which it is better to play $1 than $0.25, rather than

the

bankroll at which a $1 game is optimal. at say $13000, dollars is

too big

and quarters is too small, but dollars offers greater expected log-

utility

gain than quarters if those are your two choices. if there's a

$0.50 game,

you'd play that instead.

Ah, that makes sense. It also illustrates one of Harry's points.
That in VP, we are usually left with non-optimal bet sizes from a
Kelly perspective.

actually, it looks like using the normal distribution

overestimates bankroll

requirements, not underestimates. if i use that formula from my

last post to

calculate the threshold at which you move up from $0.99 to $1, it

spits out

$17846, which suggests that it thinks the optimal kelly bankroll

for $1 is

slightly more than that. this is over 20% higher than jazbo's

figure using

the actual distribution.

to summarize that last paragraph: it turns out to be less risky to

play a

game with limited downside than a game with unlimited downside!

now there's

a shocker :slight_smile:

Good. When it comes to bankroll vs risk, it's better to
overestimate the requirement!

i computed the exact kelly requirements myself and came up with

slightly

different numbers than jazbo (for example $14860 instead of $14585

for $1

jacks with 1% cashback), but close enough that it doesn't concern

me.

It's probably due to different values for the hand frequencies.
jazbo has different hand frequencies than WinPoker. (You can see it
at the end of his perl script link.)

At any rate, I think both RoR and Kelly are useful concepts. I've
often used Kelly to see if entering some entry-fee slot tournaments
made sense. I'd agree with you that short-term RoR is a more
practical concept than longterm RoR.

--Dunbar

···

--- In vpFREE@yahoogroups.com, fivespot <fivespot55@...> wrote:

On Dec 20, 2007 6:22 PM, dunbar_dra <h_dunbar@...> wrote:

Your gambling bankroll is the amount of your savings you have
allocated to gambling. It is not a fixed amount, it goes up and down,
depending on if you're winning or losing, depending on if your savings
investments are winning or losing, depending on if you get that bonus
this year, depending on if you decide to get a new car, etc. If you
don't know how much of your savings you have allocated to gambling, it
may be all of it, and you may have a gambling problem. If you have no
savings, you probably should not be gambling, as it is unlikely you
will win enough to have money left over when you pay the interest on
your gambling debt. The Kelly number is an easy way to determine if a
gamble is a good gamble, from the standpoint of bankroll growth. It
can be calculated exactly, but it can also be estimated easily with
the formula (variance / advantage). For example, for FPDW with .25%
cashback the estimated Kelly number is 26/(.0075+.0025)=2600. Multiply
by the amount bet per hand to get the Kelly bankroll or divide your
bankroll by the number to get your optimum Kelly bet per hand, for
example for quarter five-coin: 2600 x $1.25 = $3,250, slightly more
than three royal flushes. Exceeding the optimum Kelly bet is foolish,
what you are doing is taking on too much risk under the illusion of
winning more, but you will actually get less bankroll growth, thus the
current Banking Crisis. Of course if you can count on a bailout from a
rich uncle, that may be the proper strategy. You don't have to bet the
optimum Kelly bet, many people bet less, for example half the Kelly
bet, the result is a tradeoff of less risk to your bankroll but at the
cost of less bankroll growth, many people happily make this tradeoff
so they can sleep at night, it goes by the name of risk management.

···

--- In vpFREE@yahoogroups.com, Tom Robertson <madameguyon@...> wrote:

>so now i'm curious how many people here think their bankroll is "well
>defined".
>
>cheers,
>
>five

I've always struggled with it. Just the fact that in the time that it
takes to lose one's current "bankroll," there will likely have been
other expenses and income, which may not be easy to estimate,
particularly since it's also uncertain how long losing it will take,
makes it hard to define. The Kelly Criterion assumes a much more
"closed system" than gamblers normally face and I've just about always
gotten squeamish long before I've gotten up to the bet amount that it
would suggest based on what I thought was my bankroll, so I tend to
ignore it.

i computed the exact kelly requirements myself and came up with

slightly

different numbers than jazbo (for example $14860 instead of $14585

for $1

jacks with 1% cashback), but close enough that it doesn't concern me.

I'm catching up on some stuff, and one thing was to do the exact Kelly
calc myself (and to write a spreadsheet that will automate that!) For
9/6 JOB with 1% cashback, I get a Kelly bankroll figure of $14841,
which is much closer to your fig. Again, I think that jazbo was using
different hand frequencies. The diff between your fig and mine is
probably round-off in one or more freq's.

--Dunbar

···

--- In vpFREE@yahoogroups.com, fivespot <fivespot55@...> wrote:

Finally a rule that makes sense to me; "Commando's rule-of-thumb"

I would like to add my rule, "Gambling is only fun when betting more
than you can afford to lose."

Happy new year!! Jeep

The Commando's rule-of-thumb Risk of Ruin appraisal: If the play

bores

···

> --- In vpFREE@yahoogroups.com, fivespot <fivespot55@> wrote:
you to tears you are definitely playing within the means of your
bankroll. Conversely, if the play is very exciting to you, you are
definitely overplaying your bankroll. Good luck.