Roulette is one of those games that can sometimes be very hard to win at.
I have found that playing inside numbers and using a staking plan gives you a huge advantage over someone having absolutely no strategy and no money management at all. Sure they might walk in with no strategy and win but that is purely luck. Over the long term they will put that money straight back into the casino and walk out with less than what they walked in with.
Roulette is my favorite game to play at the casino as the odds are also very rewarding if you follow a strategy and fully understand the game of Roulette.
You can not have a strategy without a staking plan when it comes to Roulette and the same goes for having a staking plan and absolutely no strategy. You simply need to have both to give you that winning advantage.
I have seen so many people try and beat the house at Roulette by using Martingale systems like the double up on a color one, you have probably seen it before as well if you play at the casino on a regular basis. These people will keep doubling up until the color they need to win comes in. The problem with using this approach is that tables in the casinos all have table limits and when you hit that table limit using one of these chase systems and have not reclaimed your losses you are stuck.
That is why chase systems such as the Martingale do not work on even money changes like your red / black and odds and evens. It can not work because the statistics show that you can have 20 or sometimes even more runs where a color will simply sleep. Using a chase system on a lot of tables will cause you do have to bail out on the 7th or 8th spin in general.