Definition of RoR
RoR stands for "Risk of Ruin". The term is mostly used in the financial world by people who invest in the stock market, but also in poker. The most important element in calculating your "risk of ruin" is your winrate (your hourly rate at your limit, calculated as the number of big blinds per 100 hands). The higher your winrate, the less likely you are to go broke. The lower your winrate, the higher your chances of ruin.
What are the elements that allow me to calculate my RoR?
The risk of ruin is mostly variance and rake. For example, if you have a winrate of 1bb/100 hands (which is considered low) and the rake on your cardroom increases and you experience a lot of variance, you are at risk of losing. The elements to consider when calculating your risk of ruin are your winrate, your bankroll and the rake. There is one missing element in the equation, but it is never predictable: variance. If you are on a long unlucky streak where you are winning less than your expected value (EV), you are likely to go broke if your bankroll is too small.