You don't understand the formula
The question was: given a game of DD s17, das, 50%pen, no surrender, min bet 3$, 1-8 betting spread. so max bet of 25$ what is the bankroll required to insure, given the above rules and conditions, and the specified bet ranges, that I only have a 5% risk of going completely broke?
The answer is $2838 minimum. More money starting out will lower the risk of losing all, and increasing the bet levels will increase the hourly return of $6.18 that this bank roll and bet level will return.
Of course there are other factors. You could get hit over the head and robbed of your entire bankroll before you step in the casino. Should this risk be factored into the equation?
Of course their is no 'insurance'. That is stated. You have a 5% chance of losing everything. If you play 10 hours you are not going to have $61.80 profit. That hourly figure is just an 'average' over a long term period. But it is necessary.
Without some measure of Dollars per Time Period, how can you evaluate different investments or choices? Which would you choose: a high risk venture that makes you $10, or a very low risk venture that makes you $100? $100 you say? Sorry, I forgot to tell you, the $100 return matures in 30 years, while the $10 return is possible every 10 seconds. Ahhh! Now we see where time in regards to investment and return is important.
To rationally compare investments you need to have measures of $ return/time/risk. Yes, a job at McDonalds is more steady and less risky. Of course, they could fire you from that 'steady' job and then what? And after you have gotten the $6.18 return from that McDonald's job, can you then add that into your bankroll, and parlay that job into a $25 an hour job?
Do I take my $2838 bankroll and invest it into a savings account for a very low risk return of 3% in 6 months? Or do I take a 5% risk and invest it into blackjack for a 100% return in the same time period?
Or do I forget the whole thing and work at McDonald's for the rest of my life for $6.18 an hour? No mathematical formula is going to answer any of these questions, it can just put things in terms and quantities so that you can compare and decide.
Notice I never used the word 'gambling' in any of the above. When I buy a bond from GE, I am gambling that they will make money and be able to pay the stated interest on the bond. There is a risk they could go broke, and I lose all my money. Investing money in Bonds, stocks, commercial paper, mutual funds, even putting it in the bank, is gambling. They all have certian risks and returns. The nice thing about blackjack is, it is not dependent on consumer tastes, currency fluctuations, interest rates, or other outside sources. The things that effect your return in blackjack are all pretty much concrete, predictable, and measurable.
If I buy a $10 share of stock that pays a 3% dividend, does my broker tell me I would get a better hourly return working at McDonalds? Does he say if I worked at McDonalds I wouldn't need the $10 to begin with?