There is no way you will fail 7 times and if you do just increase the bet and you will get it back eventually even if you wait 12 times.
what you think on my method?
Things don't actually work like that in gambling else alot of gamblers would have adopted several means to manipulate their winning edge, but what i now see common with gamblers nowadays is that each one of them develope their own strategic means of playing gamble and if it's works they go by it but no one will want to adopt another person's own because everyone will be responsible for his money lost at the end, so if it worked for you, good luck, it may not work for others, but know that you can't be smarter than the computer and the casinos as well.