You usually call in the following situations:
- When you have calculated the pot odds and they are favorable for you;
- When you need other players to accept you as a loose player;
- When you have a strong hand but the game was opened by a tight player in early position;
- When you don’t want the player after you to re-raise;
- When you want to keep a player in the game who is bluffing and you want to keep it that way;
- When you have a chance to improve your combination later (with draw or free card /s);
- When there are only loose players at the table;
- When you think you have the same strong combination as your opponent, so the chances to win and to lose are equal;
- When you have a winning combination and you can raise but you want to keep the other players in the game since if you raise, they can fold;
- When you want to bluff later;
- When you figure that your opponent has a weak hand;
- When you need to convince your opponents that you call quite often, so you can make them stop bluffing