Well for the fact that our mentality matters a lot in whatever we are doing we have to employ a stable mentality that can allow us to make proper decisions that will help us in some ways possible that will place us in a winning position, this could also affect our winning rate at some points.
If a gambler allows his emotions to have control of his thoughts and mindset towards the game, it still can hamper his chances of winning since he may be prone to making decisions at the wrong time, since his emotions are in control.
You are right, @wiwo. For a human to perform efficiently and diligently, they must be mentally and emotionally stable; otherwise, it can result in making different kinds of mistakes. There is some kind of mental state that someone can be in, and the person can be faced with sudden amnesia, forgetting themselves about what they are doing and doing things in the wrong way even before realizing themselves. Definitely, if it's a gambler, he or she can gamble wrongly and make some mistakes that land them in possible losses that they have not planned for, plus the fact that gambling is also a game of luck. Normally, unless one is mentally good, they can't perform well, so if a gambler knows that they are not in the right frame of mind, it is better to also stay away from gambling at that moment.
Yes because mental wellness will give birth to every other productive part of the human being and if anything affect the mental state, it will result into so many negative experience for the gambler and this will not be a good outcome.
Some times, taking a enough rest also helps a lot in repairing the mental states, I have a ruin that I have maintained over the years and that is taking 2-3 hours daily to take rest during the day, this has helped me to charge up keeping me on a balanced mental state.