I love roulettes because it is very easy to play and I see it relaxing. I bet with $3.5 yesterday using martingale strategy as I want to see what the outcome would be, I was able to win $6. $6 to $9 but it will go down to $3 until I won $10. From $10 back to $6 until I won $13. Later I won $18. I played 5 consecutive times without winning at all and I lost the whole money. If won any among the 5 times selection, I would have increased it to back $18 or to $25. It was a boring day for me, I enjoyed the game, I wish to play more but I do not want to lose more money.
You describe what the failure of Martingale system it, you need a huge bankroll + luck. That's why it is not really a good system to begin with, just wondering what kind of bet you did though? red/black? or 1-18 or 1-36.
Although I used this system from time to time in baccarat, and I will only go for 3 straight consecutive wins and then I will stop and reset or completely just "cool-down" and not force myself to continue with this strategy, but having like 4 or more consecutive losses, it's already a disaster.