Yep knowing to stop is a key part of gambling, if you know when to stop you have already made 50% of the job in betting game, if you cant control your impulses you will get constantly fucked by the odds, so you must run with your profits as soon as possible. Oh and when it comes to trading is the same, you must set stop losses and know when you fucked up and run with the money.
smart way to gamble can you find if you can control yourself in the game. but, it is very difficult to do that, in fact very few people who can do that. many people who try it, but in the end they got stuck in a gambling game. if you want to try, try to use the number of bets a little, but do not let you be tempted to keep playing, because it is common.