Quite a large House Edge at roulette. Even using different manipulations with bankroll management, you will still lose it.
We draw a simple conclusion - there are no working strategies for roulette, only luck on a short distance and stop playing it.
^ And additional, the more time you have spent, the more chances of losing your money.
All based on house edge games are no strategy, probably there is but only martingale which is very risky and will easily wipe out your entire balance.
Just like dice, roulette game is almost the same.