On Apr 12, 2012, at 12:37 PM, GURU PERF wrote:
> 1.) I watched, at about 3AM one night, a casino employee open each
> VP/slot muliti-game, multi-denom machine along an entire bank
> (except the one I was playing) and manually record the data on each
> option on the machine. I could only see the actual numbers on the
> machines adjacent to me, but the VP payout % was pretty close to,
> but consistently below, the machine's ER for the various games, as
> would be expected. The slots were all in the 80-something % range.
>
It's fun to look at actual machine data. At one casino, the Aruze
slots are recorded every 2nd week - usually Monday morning.
The screens include number of lifetime payouts between $500-1,000,
$1,000-2,000, etc...,
so you can see which machines are paying out more large jackpots.
On one slot, which claims better than 95% payout at max bet, the
payouts are set to 95.04% at max bet.
At lower bets, the payouts are 86-89%...and the ones in the "high
paying slot zone" are set no differently than the ones outside.
Some of my favorite slots are set low; e.g. 92.5% for a Double Diamond
Mine $1.
On Apr 12, 2012, at 10:35 AM, kelso 1600 wrote:
> Casinos keep detailed records on the win/loss of each machine which
> is required in most gaming jurisdictions. Depending upon the
> jurisdiction these records are either reviewed and/or sent to the
> appropriate gaming jurisdiction. Any machine that has a significant
> deviation from the expected win/loss is replaced.
>
...only if the casino management is doing their job.
Last year, the head casino director was fired at one casino.
The Hee Haw slot bank had reduced the max bet from $6 to $3, but left
all three progressives the same (so they were paying double).
I "heard" that the casino lost ~$300,000 during the 6+ months that the
machines were mis-set.
One of my friends won three $6,000 jackpots which should have started
at $3,000.
-----
At the Palazzo and Red Rock in Vegas, I saw Video Poker machines shut
down the day after big wins.
The next day Palazzo replaced the $2-$5 Jacks 9/6 with Jacks 9/5.
Red Rock shut down a whole bank of ten 10-play machines. I forget
whether they were downgraded.
On Apr 12, 2012, at 9:07 AM, nightoftheiguana2000 wrote:
> Your best guess before hand effects the Bayesian inference:
>
> http://en.wikipedia.org/wiki/Bayesian_inference
>
> Basically, you're using a test which always has a chance of false
> negative and false positive. Bayesian inference is a technique to
> adjust your previous assumption to the results of your data knowing
> that there is a certain false report rate. For example, you might
> assume that the ER of a certain machine is 100.76% with perfect
> play. After taking data, you can make a Bayesian inference on what
> the actual ER is, which will include your play error rate.
>
"A priori" beliefs affect the interpretation of data.
For example, with an AIDS test which has 99% accuracy, if you get a
positive result, and you believe you are not infected (e.g. chance
<1/10,000),
then the positive result probably is wrong.
If I walk into a casino where I have been told the games are rigged
(e.g. chance >50% that the games are set too low or the video-poker-
plays-like-a-slot),
I may decide with only minimal data (< 1 SD loss) that the games are
indeed rigged.
-----
Another factor is that "computer chips are NOT random". They use
random number generators which are designed to have certain behaviors
(e.g. average payout = 98.3%, certain percentages of each hand, etc...)
They can exhibit behaviors very unlikely for truly random cards (and
real cards are not random either...);
e.g. I hold 4 to a flush on a 10-play, and get 6 flushes, 5 with the
"6 of hearts".
Video poker (in my observation) is very streaky.
In statistics (for a normal distribution), I might describe this as
high "peaked-ness" (or the third moment being rather high).
Mean = 1st moment
Variance (Standard Deviation) = 2nd moment
Peakedness = 3rd moment
Skewness = 4th moment
etc...
Designers often check for a mean & standard deviation of a pseudo-
random algorithm to operate within certain parameters.
However, they might not pay attention to the 3rd, 4th, and higher
moments.
This has caused MANY problems for computer simulations, which
calculate faulty results (based on an expectation of randomness).
Thus, it's entirely possible to design a video poker chip which gives
98.6% payout, but has a lower-than-expected number of four-of-a-kinds,
...and a higher percentage of some other hands.
Mitchell
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