It is your precious money and the only thing that connects you to the game. Because the casino has unlimited bankroll and yours is limited. According to some mathematicians this bankroll discrepancy between the player and the casino is the number one reason why gamblers lose. Your bankroll is your hard earned money, or the money you won the previous session, or the previous day or the previous month or the previous year in the casino, which I would call hard earned too. That money is important. When that money is gone you are out of the door. The bankroll is one of the three most important things you have in the game of roulette. The other two things are a good roulette system and your mind.
Be ready to lose it. But don't lose it without a fight. Never lose it like a robot. Any amount can be a serious bankroll if the gambler is serious and has a mission, a serious plan. To spread money aimlessly on the roulette table is not working with a bankroll. It is simply entertainment cost. Nothing is bad with spending money to have fun, but let's be clear at least about definitions. Show respect. Have a plan. Play disciplined.
Your bankroll is actually the only thing you really know about your session. You don't know the next spin, you may not know exactly the strong and weak spots of your system, you may not know when to stop, but you do know your money. It is a great indicator and something absolutely real. Your money is a fact. You see it increasing and decreasing and you know when it's over it's over. This is why some of the most ingenious systems I know take your bankroll into account. You can even modify progressions like the Martingale or Oscar's Grind to take your bankroll into account and they suddenly transform them to powerful and smart systems. Taking your bankroll into account is one of the best ways to follow the trend too. What simpler indicator than this: if your money is decreasing the trend is against you, if it is increasing the trend is in your favor. Most progressions take into account your wins and losses. But taking into account your bankroll directly is a different thing. For example let's say you have a specific bankroll and you decide to bet the even chances with a 3-step Martingale. When your bankroll increases you can start betting a 4-step Martingale and when it depletes you can go to a 2-step Martingale. This is just to help you understand what I mean by taking into account your bankroll.
The bankroll is one of the most important aspects of roulette. One must respect its power and understand its various aspects. One can use it as an indicator and even create a system based on it. And there is much more to learn about it. Two of the benefits of playing roulette online are that you may have a better and more detached supervision of your bankroll and that there is no need to tip the dealers.