There are many betting strategies in gambling. There are specific betting strategies for each game casino game. Martingale and Anti'Martingale are well known and popular.
Martingale betting system
If you use Martingale system, you double your bets every time you lose. If you win, you return to initial bet amount. For example, you place 1 coin and lose. Next you place 2 coins and lose. You place 4 coins and win. You win 1 additional coin (8-7).
Many roulette players love this betting strategy. But there are some problems using this strategy. First, you must have big, very big bankroll to use Martingale strategy. You must have 63 coins in bankroll for 5 spins long losing series, and 127 coins for 6 spins long losing series.
Second, you must find roulette table with wide bet size limits range.
If you use Martingale betting system, you increase risk then you lose. This is the way to losing all your money!
AntiMartingale betting system
Now you double your bets then you win. If you lose, you place initial bet amount. For example, you bet 1 coin and win. Next you bet 2 coins. And so on. Limit size of largest bet amount. If you start from 1 coin, it may be 4 or 8 coins. Then you rich this limit return to initial bet size.
This system is much better than Martingale system. There is no bankroll size limitation. And casino limits don't disturb you.
Using AntiMartingale betting system you increase risk then you win. Many professional gambling players use this betting strategy.
Remember. You can use Martingale or Anti'Martingale system. But do not play under emotions influence. Control yourself. If you have bad day, stop playing. Go to the bar or go home.
If you can't stop, you need professional help. You become compulsive gambler.
Gambling is entertainment. Roulette is just a game. Enjoy youself, and you become lucky guy.