vpFREE2 Forums

Dunbar · January 14, 2020, 6:32pm

Shouldn't there be a correlation for ROR to variance in games that
are both close in total payback? By your own analysis, the higher
ROR for Pick em comes from so much of the EV being tied up in the
quads, well isn't that where variance usually comes from?, which

is

why a 10/7 DB has a higher variance than 9/6 JOB though it has a
higher total payback.

There is probably a correlation of LONGTERM RoR to variance, for
games of similar payback. (which is only a meaningful statement if
the payback is >100%.) But the SHORT-TERM RoR is very dependent on
just how the payoffs are structured. As the PickEm example shows, a
game with smaller variance can have a bigger Short-Term RoR.

--Dunbar

>
> I did the "simpler" test that I described below. Here is what I
did.
>
> 1. I found the session bankroll that you would need in order to
have
> a 2% RoR after 8000 hands of single-line 25c 9/6 JOB.
>
> 2. I used the ratio of variance to estimate what session

bankroll

> would be needed to play NSUD and Pick'em with the same 2% RoR as
JOB.
>
> 3. I then calculated the actual RoR for those bankroll estimates
and
> compared the result to 2%.
>
> Here's what I found:
>
> 1. It takes $700 to have a 2% RoR for 8000 hands of single-line
25c
> 9/6 JOB. (according to Dunbar's Risk Analyzer for Video Poker)
>
> 2. JOB variance is 19.51; NSUD variance is 25.78; Pick'em

variance

> is 15.01.
>
> The variance ratio of NSUD to JOB is 25.78/19.51 = 1.32, and the
> predicted session bankroll for a 2% RoR would be $700 * 1.32 =
> $924.96.
>
> The variance ratio of Pick'em to JOB is 15.01/19.51 = 0.77, and
the
> predicted session bankroll for a 2% RoR would be $700 * 0.77 =
> $538.54.
>
> 3.
> NSUD: Using a $924.96 bankroll for 8000 single-line hands,

there

> is a 2% RoR, same as for JOB. That was encouragingly. But...
>
> Pick'em: Using a $538.54 bankroll for 8000 single-line hands,
there
> is a 13% RoR. That's too far from 2% to be useful.
>
> In fact, even a $700 session bankroll in 25c Pick'em has a 4.5%
> RoR. The game with the smaller variance has the bigger RoR!
After
> thinking about it, I decided it made sense. Pick'em has 5% of

its

> EV tied up in quads or better, and quads occur about once every
2000
> hands. It's easy to have a significant shortage of quads in

just

> 8000 hands. JOB, on the other hand, has just 2.5% of its EV

tied

> up in rare hands.
>
> If you looked at a longer "session", Pick'em would have the

lower

> RoR for the same bankroll.
>
> None of this proves or disproves Lainie's suggestion. It only
shows
> that the suggestion cannot be generalized to comparing different
> games. We probably already knew that, but I thought I'd check

it

> anyway.
>
> Dan Paymar's new data will be a good test for Lainie's

suggestion.

···

--- In vpFREE@yahoogroups.com, "caplatinum" <belairgold@...> wrote:

--- In vpFREE@yahoogroups.com, "dunbar_dra" <h_dunbar@> wrote:
>
> --Dunbar
>

Dunbar · January 14, 2020, 6:32pm

Lainie hypothesized that perhaps one could estimate the session
bankroll of an n-play game if one knew the session bankroll of a 1-
line game and the variance of the two games. She suggested that the
ratio of the variances might be a good estimate of the ratio of the
session bankrolls. She asked for help in testing her hypothesis.

(see http://groups.yahoo.com/group/vpFREE/message/62061)

I have done some calculations, and the results do not appear to
support Lanie's idea.

TEST: 10-play session bankroll=500 units, 10,000-unit coin-in

1. A 10-play with 500-unit bankroll has 28% RoR after 1000
plays (data from current issue of Dan Paymar's VP Times, which Dan
was kind enough to send me by email)

2. The variance of 10-play JOB is 1.9 times the variance of 1-
play, according to jazbo's website.
(http://jazbo.com/videopoker/nplay.html)

3. Lainie's hypothesis would predict that a 1-play session
bankroll of 500/1.9 = 263 units (dividing by the variance ratio)
would also have a 28% RoR after the same coin-in (10,000 plays)

4. However, a 263-unit bankroll on 1-line JOB results in an RoR
of 53%, not 28%. It takes about 380 units to get a 28% RoR in
10,000 plays of JOB. (data from using Dunbar's Risk Analyzer for
Video Poker).

Turning it around, you need 500/380 = 132% as much bankroll to play
10-play for the same 10,000 unit coin in. (not 190%)

I did the same calculation for 20,000 unit-in. The 10-play with a
1000-unit bankroll had a 13% RoR. But the predicted 1-play session
bankroll (526 units) has a 38% RoR instead of 13%. (It takes about
775 units to have a 13% RoR. Thus, you need 129% as much bankroll
to play 10-play for 20,000 unit-in.

I've compared some of Dan Paymar's numbers for 1-line JOB to figures
generated by Dunbar's Risk Analyzer, and they agree to within the
standard error of the data. I cannot evaluate Dan's n-line figures,
but I have no reason to think they are incorrect. They are
internally consistent. Congrats to Dan--these are the first n-play
session bankroll vs RoR tables that I remember seeing.

I am also accepting jazbo's n-play variance calculations at face
value. For me, at least, it is not a trivial task to reproduce the
covariance value that goes into calculating the variance of n-play.

If Dan's figures and jazbo's figures are correct, and I think they
are, then it appears that a simple comparison of variance will not
yield useful session bankroll estimates for n-play games. This is
exactly what Harry Porter emphatically predicted in his recent post.

The amount of extra bankroll you need to play n-play will decrease
as the amount of play increases. In fact, with 320,000 units coin-
in, there is very little bankroll difference between 1-play and 10-
play!

--Dunbar

Thanks for your responses Dunbar, BL, John, Dan, Harry and Jean.

I've been thinking about your responses, and I think some background
would be helpful -- so I'm not asking my questions in a vaccuum.

I typically play quarter 9/6 Jacks (or other games that allow me

to use that strategy since I know that I make mistakes when I switch
between games that require different strategies). I estimate that
with my dedicated VP bankroll and restricting my play to casinos
that offer enough CB and BBC to make the plays positive, I have
almost no ROR.

That being said, when I go out to play, I have a "coin-in" goal

for the session. I use "coin-in" goals because they allow me to
maximize slot club program benefits. Because of my approach, it's
vital that I reach my "coin-in" goal each time I play, and I have to
make sure I have enough of a session bankroll with me to allow me to
reach my goal.

When I used to play FPDW, I noticed that I had many sessions

where I was under-bankrolled and lost my entire session bankroll
before the session was able to turn around. When I started bringing
a larger session bankroll, I was usually able to turn things around
and not lose more than a few hundred dollars in a session.

I learned that my experiences were due to the game's fluctuation

and that by looking at a game's variance, I could gauge
fluctuation. I know that the higher the variance, the larger the
session bankroll needed to reach a specific "coin-in" goal.

Lately, I've had less time available to play, yet I still want

to reach my "coin-in" goals. Also, since just playing single line
9/6 Jacks gets boring, I've been looking for ways to add some
excitement. Thus, N-play games are a great solution for me.

Now, I get to the hard part. When I can find fifty or hundred

play nickels, I've experienced that my usual quarter session
bankroll seems to be sufficient for playing 20-25 lines, even though
I'm going from betting $1.25 per pull to $5.00-$6.25 -- and that
same bankroll would not be sufficient for playing single line
dollars ($5.00 per pull). I've also noticed that double my usual
quarter session bankroll seems to be sufficient for fifty play
nickels or two cent hundred play, and I assume that that's because
the increased number of lines mitigates the fluctuation.

While I'm not a "math person," I am a "logic person," and I've

come up with an approach that I think may work to estimate the
session banroll needed for N-play games. Unfortunately, I don't
have the skill to test my theory. Since many of you possess skills
that are far superior to mine, I'm wondering if you could test my
theory, see if you think it could work and help me...

  Here's the approach:

  1. Calculate the session bankroll required for $10k coin-in of

single line 9/6 Jacks.

2. Calculate the variance for ten, fifteen, twenty, twenty

five, fifty and hundred line 9/6 Jacks (using the co-variance).

3. Using the ratio of session bankroll required for single line

play to its variance, extrapolate the session bankrolls required for
ten, fifteen, twenty, twenty five, fifty and hundred play (based on
the variances calculated in step 2 above).

4. Sanity check the answers by comparing the estimated session

bankroll requirements for N-play games with session bankroll
requirements for single line games that have similar variances. So,
hypothetically, if the variance for fifteen play 9/6 Jacks is 22.153
(and I'm just making that up), logically, the session bankroll
required should be very similar to the session bankroll required for
single line 9/5 DJ, which has a variance of 22.106.

  What do you think of this approach?

  Thanks for your help.

  Lainie

dunbar_dra <h_dunbar@...> wrote:
          Lainie, to expand a bit on what Harry and bl wrote...

You can use variance to get an estimate of where you might end up
after a session. The shorter the session, the rougher the estimate
will be.

Even so, you cannot use variance to estimate a session bankroll
requirement. That is because the endpoint "picture" does not
reflect what may have happened during a session. If you start with
a $500 "bankroll", there will be many instances where you lose

$500,

but if you keep playing you end up in positive territory. Using
variance misses those instances.

Another way of saying this is re-writing my first sentence
can use variance to get an estimate of where you might end up

after

a session, if you have an unlimited bankroll."

--Dunbar

>
> Thanks John, this really helps (as did Jazbo's site). I really
appreciate all your effort.
>
> Reading through this -- and thinking about the implications, I
was wondering what you (and everyone else) think about whether
players could use this to calculate the variance for the variety

of

multiplay that they want to play and then use that variance (and

the

denomination they're going to play) to estimate the session

bankroll

requirement.
>
> Put differently, I'm confident that I could put this data into a
spreadsheet and come up with the variances that I would have

playing

···

--- In vpFREE@yahoogroups.com, Lainie Wolf <lainiewolf702@...> wrote:
to: "You

--- In vpFREE@yahoogroups.com, Lainie Wolf <lainiewolf702@> wrote:
10-play, 25-play, etc. Then, I wonder if I could use each variance
to estimate the associated session bankroll.
>
> Thoughts?
>
> Thanks,
> Lainie
>
>

murphyfields · January 14, 2020, 6:32pm

Reading through this thread, I would love to have some short-range
statistic that is closely related to RoR, but has a little more
meaning for my particular interests. Something similar to Jazbo's
survivability curves.

I would like to be able to choose a specific game, and a desired
number of hands (or equivalently a desired coin-in goal), and a
desired probability of reaching that goal.

So, if I choose single-hand quarter 9/6 JoB, and would like to have
8000 hands or $10,000 coin-in, what session bankroll do I need to have
a 90% chance of success. What about 99%?

The down side of this dream is that there are just too many variables.
Different machines, different goals, different acceptable risks. If
we could narrow things down a little, it might be possible to generate
the values we need.So how much coin-in would people like to see
evaluated? Would $100, $1000, $10,000, $100,000, and $1M be enough to
suit everyones needs. What success rates? 50%, 75%, 90%, 95%, 99%?
Any others? And what games? And what about multiple play machines.
Is 1x, 2x, 3x, 4x, 5x, 10x, 50x and 100x adequate.

Of course exact answers are better than simulations, but simulations
might give some good quick-and-dirty answers. If someone could write a
simple Monte-Carlo simulator and make it available, the task could be
divided up between many users, giving results a little more quickly.

So, would these results be useful, or would something else be better?

- John

Harry_Porter · January 14, 2020, 6:32pm

murphyfields wrote:

I would like to be able to choose a specific game, and a desired
number of hands (or equivalently a desired coin-in goal), and a
desired probability of reaching that goal.

You've identified on of the strengths of Dunbar's Risk Analyzer for
Video Poker. Check it out.

http://www.shoplva.com/ProductDetail.cfm?ItemNumber=1463

- H.

Richard_Boozer · January 14, 2020, 6:32pm

What does "sucess" mean? Surviving the coin in? or
coming out positive?

···

--- murphyfields <jkludge@juno.com> wrote:

Reading through this thread, I would love to have
some short-range
statistic that is closely related to RoR, but has a
little more
meaning for my particular interests. Something
similar to Jazbo's
survivability curves.

I would like to be able to choose a specific game,
and a desired
number of hands (or equivalently a desired coin-in
goal), and a
desired probability of reaching that goal.

So, if I choose single-hand quarter 9/6 JoB, and
would like to have
8000 hands or $10,000 coin-in, what session bankroll
do I need to have
a 90% chance of success. What about 99%?

The down side of this dream is that there are just
too many variables.
Different machines, different goals, different
acceptable risks. If
we could narrow things down a little, it might be
possible to generate
the values we need.So how much coin-in would people
like to see
evaluated? Would $100, $1000, $10,000, $100,000,
and $1M be enough to
suit everyones needs. What success rates? 50%,
75%, 90%, 95%, 99%?
Any others? And what games? And what about
multiple play machines.
Is 1x, 2x, 3x, 4x, 5x, 10x, 50x and 100x adequate.

Of course exact answers are better than simulations,
but simulations
might give some good quick-and-dirty answers. If
someone could write a
simple Monte-Carlo simulator and make it available,
the task could be
divided up between many users, giving results a
little more quickly.

So, would these results be useful, or would
something else be better?

- John

murphyfields · January 14, 2020, 6:32pm

I may have to buy the new copy when it comes out. But what can be
done about multi-play games?

- John

···

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

murphyfields wrote:
> I would like to be able to choose a specific game, and a desired
> number of hands (or equivalently a desired coin-in goal), and a
> desired probability of reaching that goal.

You've identified on of the strengths of Dunbar's Risk Analyzer for
Video Poker. Check it out.

http://www.shoplva.com/ProductDetail.cfm?ItemNumber=1463

- H.

murphyfields · January 14, 2020, 6:32pm

For my purposes, success means surviving the coin in. I have a
specific coin-in goal going into the casino. If I reach it without
losing everything, I count the trip a success.

- John

···

--- In vpFREE@yahoogroups.com, Richard Boozer <reboozer@...> wrote:

What does "sucess" mean? Surviving the coin in? or
coming out positive?

--- murphyfields <jkludge@...> wrote:

> So, if I choose single-hand quarter 9/6 JoB, and
> would like to have
> 8000 hands or $10,000 coin-in, what session bankroll
> do I need to have
> a 90% chance of success. What about 99%?
>

Dunbar · January 14, 2020, 6:32pm

murphy, for 8000 plays on a 1-line 25c JOB game, you'd need $545 to
have a 10% RoR. You'd need $750 to have a 1% RoR.

Even with the 10% RoR, you would have just a 2% chance of getting
less than 5600 plays (70% of the intended play) before going broke.

These figures ignore the effects of cashback, tips, and errors, all
of which can be factored into the calculation by Dunbar's Risk
Analyzer for Video Poker.

--Dunbar

···

--- In vpFREE@yahoogroups.com, "murphyfields" <jkludge@...> wrote:

For my purposes, success means surviving the coin in. I have a
specific coin-in goal going into the casino. If I reach it without
losing everything, I count the trip a success.

- John

--- In vpFREE@yahoogroups.com, Richard Boozer <reboozer@> wrote:
>
> What does "sucess" mean? Surviving the coin in? or
> coming out positive?
>
>
>
> --- murphyfields <jkludge@> wrote:
>
> > So, if I choose single-hand quarter 9/6 JoB, and
> > would like to have
> > 8000 hands or $10,000 coin-in, what session bankroll
> > do I need to have
> > a 90% chance of success. What about 99%?
> >

Lainie_Wolf · January 14, 2020, 6:32pm

Dunbar, thanks much for the analysis. (Dan, thanks also for sharing your work with Dunbar, and Jazbo, thanks too for sharing your work with everyone...) I'm sorry to hear that I was wrong, but I really do appreciate everyone's effort.

  Because of my poor statistics skills (one intro course at a community college over 20 years ago), I'm still not sure I fully comprehend, but I'm going to keep trying.

  Best,
  Lainie