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# Gaming Guru

### Ask the Slot Expert: Risk analysis and video poker, Part 2

21 April 2021

Question: I usually play Hot Roll Video Poker, ten hands at 5-cent, 10-cent and 25-cent denomination. The game of choice is 8/5 Double Double Bonus or 9/5 for 25-cent denomination. This is all we have here in Boston. Each bet is \$5, \$10, and \$25, respectively.

The question is: What is the bankroll requirement for each of these denominations to have a 1% and 5% risk of ruin?

Answer: This week we'll take a closer look at one of the products that analyzes your risk playing video poker, Dunbar's Risk Analyzer for Video Poker, a set of Excel macros.

You can read about the math behind how the Excel macros work in Risk of Ruin for Video Poker and Other Skewed-Up Games. Following the article can be rough sledding at times, but it's very similar to many of Don Catlin's articles on this site. Both authors start with a simple formula, build on it to progressively more complex formulas, and arrive at a solution for the problem at hand. You may have to read the article a few times -- I did -- paying attention to how Dunbar uses things we learned before in each step.

At least there's a minimum of Greek letters. I don't remember being overwhelmed by Greek letters in my first semester of statistics. But the second.... Every formula looked like a Greek Scrabble tile rack. The first semester professor was from Bath, Maine. He had a vaguely British-like accent. The professor for the second semester had a heavy Eastern-European accent. And bad handwriting. We should have had a lesson on the Greek alphabet before starting with the math.

For a description of the many capabilities of the macros, see Henry Tamburin's interview with Dunbar.

As I said before, the Risk Analyzer is a set of Excel macros. The product ships as an XLS file that you open in Excel.

I'm using it for the first time. Let's see if I can answer this question: How large a bankroll do I need to have a 5% risk of ruin playing 10-hand 9/5 Jacks at \$25 per play. For the time being, we'll ignore the Hot Roll gimmick. As I said last week, the Wizard of Odds was kind enough to show us that the math of the Hot Roll gimmick makes the long-term payback for a Hot Roll paytable the same as the paytable without the gimmick. The only thing we buy with the extra bet that activates the gimmick is increased volatility.

The first step after opening the workbook file in Excel is probably to enable the macros, now that Microsoft is taking security seriously. (Many years ago at Windows programming seminar, the speaker was teaching how to use a particular API call in Windows. One of the parameters was a security object. He said, "Of course, we pass in NULL. Probably shouldn't, but that's what we do.")

Now we have a choice. We can either analyze one game or a series of games. The latter option lets you calculate bankroll requirements for a buffet of games you plan to play on a trip. We only want to analyze 9/5 Jacks, so we'll pick that in the Select One Game dropdown and click the GO button.

Next you get a rather intimidating page of boxes of different colors. It's much like a crap table -- you can ignore most of it until you want to use a feature. There's a good help screen you can bring up. Plus, the screen has text to guide you through the steps. You enter parameters in the yellow boxes. The blue boxes have captions and calculation results.

Step 1 is entering the parameters for the calculations. We want to play 10 hands, quarters, 10 coins per hand. Enter 0.25 for Coin Size and 10 for Number of coins. And this is a good time to notice that to the left of where we're entering this data is a dropdown to let us specify the number of lines we want to play. Choose 10-play.

Let's leave the rest of input boxes blank, even Hourly cost of errors. We all play mathematically perfectly, don't we?

Step 2 tells us to click on a button to calculate either the Long-term or Short-term RoR (Risk of Ruin). We didn't enter anything into the Trip RoR parameters box above the Short-term button, so let's click Long-term. A warning pops up: "The game you have defined has no longterm player advantage. Therefore, the longterm risk of ruin will be 100% regardless of the size of the bankroll." The warning box goes on to ask if we forgot to include Cashback (which may make the game positive). Finally, "it IS possible to do Short-term risk of ruin calculations even when a game has no long-term player advantage."

We're still in business. We'll have to go back to the Trip RoR parameters we ignored before so we can run short-term calculations.

We have to switch from the long term to the short term. Time on video poker machines is measured in number of hands not ticks of a clock. The page wants us to enter how long we want to play and how quickly we play.

I almost always play a certain number of hands and I don't know how quickly I play and I don't keep track of how long I play. I think most VP pros also plan to play a certain number of hands, especially when a point multiplier is capped. (I learned the hard way that casinos notice if you always quit playing once you've maxed out. Don't do that.) The product is the only thing that matters. We can just enter any two numbers that yield the number of hands we're going to play when multiplied.

It's usually very easy for machine players to know exactly how many hands or spins they've played by looking at the slot club display. Table games players usually aren't tracked as finely. They don't know how many hands they've played. The table games players I know usually plan to play a certain length of time.

We have to enter the number of hours we want to play and the number of hands we play per hour. My correspondent didn't give this information, so let's guess. He's in Boston so I'll guess he's local and we'll plan on a day trip of four hours playing 400 hands per hour. We also have to enter our bankroll.

Wait a minute! Isn't that what we're trying to calculate?

Yes, it is. But there's a problem. The analyzer can take a bankroll, a paytable, and the number of hands played and calculate risk of ruin. But it's a one-way street. We can't start with the desired risk of ruin and other parameters and work our way backwards to bankroll. We can find the bankroll that will give us the desired risk of ruin, but we'll have to try multiple bankrolls to home in on the desired result.

Let's bring \$1000 to the casino. Probably not nearly enough to play \$25 per hand, but our risk is spread over 10 hands. Click Calc Short-term RoR and the answer appears quickly. That bankroll gives us a 69% RoR.

Yikes. Let's try \$2000 just to see how quickly the RoR falls. RoR is now 29%. Sweet. We may not need a wallet overflowing with Benjamins to reach our goal.

I tried various bankrolls and got about a 5% RoR at \$3075. About \$3700 will give an RoR around 1%.

Two things to keep in mind. We're not dealing with the increased volatility for Hot Roll, so the bankrolls will really need to be a bit higher.

The other thing to keep in mind is randomness. One of the short-term parameters is Number of trials. The process plays the number of hands you specify that many times and keeps track of the results of each trial. The default number of trials is 1000. You won't necessarily get the same RoR each time you calculate with the same parameters.

Sometimes you're lucky. Sometimes you're not. Sometimes the process is lucky. Sometimes it's not.

Here are the latest figures from https://www.cdc.gov/covid-data-tracker/#cases_totalcases.

Totals Weekly Increases
US NV US NV
Date Cases  Deaths  Cases  Deaths  Cases  Deaths  Cases  Deaths
04/20   31,541,447   564,813   310,933   5,368   464,556   5,072   2,590   36
04/13   31,076,891   559,741   308,343   5,332   480,061   5,321   2,986   57
04/06   30,596,830   554,420   305,357   5,275   448,935   7,124   3,084   38
03/30   30,147,895   547,296   302,273   5,237   439,510   6,793   939   63
03/23   29,708,385   540,503   301,334   5,174   388,928   7,446   1,863   53
03/16   29,319,457   533,057   299,471   5,121   381,695   8,362   3,078   81
03/09   28,937,762   524,695   296,393   5,040   480,902   11,573   2,413   83
03/02   28,456,860   513,122   293,980   4,957   463,356   14,129   2,835   75
02/23   27,993,504   498,993   291,145   4,882   451,083   13,923   2,406   162
02/16   27,542,421   485,070   288,739   4,720   602,906   21,411   4,149   198
02/09   26,939,515   463,659   284,590   4,522   779,305   21,828   5,444   244
02/02   26,160,210   441,831   279,146   4,278   1,007,777   22,004   7,249   249
01/26   25,152,433   419,827   271,897   4,029   1,312,565   23,385   10,324   250
01/19   23,839,868   396,442   261,573   3,779   1,317,119   21,318   11,324   279
01/12   22,522,749   375,124   250,249   3,500   1,790,345   22,660   17,217   294
01/05    20,732,404   352,464   233,032   3,206   1,499,561   18,435   14,655   233
12/29   19,232,843   334,029   218,377   2,973   1,258,540   15,460   12,493   186
12/22   17,974,303   318,569   205,884   2,787   1,656,411   18,537   16,472   239
12/15   16,317,892   300,032   189,412   2,548   1,494,763   17,247   18,825   229
12/08   14,823,129   282,785   170,587   2,319   1,375,502   15,483   18,418   175
12/01   13,447,627   267,302   152,169   2,144   1,114,175   10,286   15,942   121
11/24   12,333,452   257,016   136,227   2,023   1,197,199   10,784   14,130   106
11/17   11,136,253   246,232   122,097   1,917   1,099,790   8,501   11,115   65
11/10   10,036,463   237,731   110,982   1,852   767,645   6,838   8,868   68
11/03   9,268,818   230,893   102,114   1,784   588,207   5,809   5,936   35
10/27   8,680,611   225,084   96,178   1,749   492,026   5,585   5,238   (10)
10/20   8,188,585   219,499   90,940   1,759   401,037   5,053   4,501   48
10/13   7,787,548   214,446   86,439   1,711   351,270   4,886   3,910   48
10/06   7,436,278   209,560   82,529   1,663   306,965   4,962   3,232   36
09/29   7,129,313   204,598   79,297   1,627   303,616   5,136   3,058   54
09/22   6,825,697   199,462   76,239   1,573   288,070   5,370   2,196   82
09/15   6,537,627   194,092   72,043   1,491   250,265   5,404   1,825   65
09/08   6,287,362   188,688   72,218   1,426   282,919   5,638   2,734   92
09/01   6,004,443   183,050   69,484   1,334   251,790   5,291   3,237   104
08/25   5,752,653   177,759   66,247   1,230   330,411   7,889   4,076   125
08/18   5,422,242   169,870   62,171   1,105   358,071   7,463   4,973   114
08/11   5,064,171   162,407   57,198   991   365,353   7,203   5,776   117
08/04   4,698,818   155,204   51,422   874   418,683   7,532   7,367   109
07/28   4,280,135   147,672   44,055   764   460,996   7,042   7,130   91
07/21   3,819,139  140,630  36,195  674  463,682  5,395  8,181  57
07/14   3,355,457   135,235   28,744   617   422,861   5,102   5,607   57
07/07   2,932,596   130,133   23,137   560   351,367   3,394   5,006   24
06/30   2,581,229   126,739   18,131   536   278,941   6,406   4,367   26
06/23   2,302,288   120,333   13,764   510
John Robison

John Robison is an expert on slot machines and how to play them. John is a slot and video poker columnist and has written for many of gaming’s leading publications. He holds a master's degree in computer science from the prestigious Stevens Institute of Technology.

You may hear John give his slot and video poker tips live on The Good Times Show, hosted by Rudi Schiffer and Mike Schiffer, which is broadcast from Memphis on KXIQ 1180AM Friday afternoon from from 2PM to 5PM Central Time. John is on the show from 4:30 to 5. You can listen to archives of the show on the web anytime.

#### Books by John Robison:

The Slot Expert's Guide to Playing Slots
John Robison
John Robison is an expert on slot machines and how to play them. John is a slot and video poker columnist and has written for many of gaming’s leading publications. He holds a master's degree in computer science from the prestigious Stevens Institute of Technology.

You may hear John give his slot and video poker tips live on The Good Times Show, hosted by Rudi Schiffer and Mike Schiffer, which is broadcast from Memphis on KXIQ 1180AM Friday afternoon from from 2PM to 5PM Central Time. John is on the show from 4:30 to 5. You can listen to archives of the show on the web anytime.

#### Books by John Robison:

The Slot Expert's Guide to Playing Slots