How computers guess correctly playing cards without input from the user?

you receive a email with a .pps or java attachment, or enter to a website where a program guess the correct card or symbol whithout any input of you, except the point you stare at.

How computers guess correctly playing cards without input from the user?
They don't. I think I know what you're talking about; you have to think of a number, then perform a calculation with it number, which always has a particular result --e.g. it's always a multiple of 9. Then you have to look up that result in a list; in aforementioned example, the numbers 9, 18, 27, etc., all have the same symbol next to it in the list.
Reply:These are psychological and mental games. You don't have to do anything. What the program is designed to do is make the best possible guess on what you will choose based on average human behavior OR they are based on impossible-to-beat odds such as the card games that make you jump your choice from one to another.