There is no definitive answer to this question, as it depends on a variety of factors specific to each individual game. However, some general guidelines can be helpful in making informed decisions.
In general, it is generally advisable to fold when it becomes clear that you are not going to be able to win the hand. This is especially true when you are facing a particularly difficult opponent, or when the hand is going against you in terms of odds.
Additionally, it is important to remember that there is no shame in folding when the game is close. In fact, doing so can often result in a much better overall experience for both you and your opponent.
