No one can learn – by looking at your face – if your cards are good or bad.
People now use poker face in everyday speech to describe someone who shows no emotion.
Someone who has a poker face usually is good at bluffing . Bluffing is trying to trick a person into believing something about you that is not true.
In poker, you bluff when you bet heavily on a poor hand. The idea is make the other players believe you have strong cards and are sure to win.
If they believe you, they are likely to drop out of the game. This means you win the money they have bet.
You can do a better job of bluffing if you hold your cards close to your vest.
You hold your cards close to you so no one can see what you have.
In everyday speech, holding your cards close to your vest means not letting other know what you are doing or thinking. You are keeping you plans secret.