Are you fan of inside betting in roulette? How many numbers do you like to bet? If you pick one number only, it could take 1 spin to 500 spins(or even more) to get just one hit. No progression will help.
How about two? Hmm. any random pick of two numbers may take you upto 200 spins for its maiden hit in worst days. Same goes for any set of numbers, irrespective of how you choose them.
Can we make it safer, slightly?