Step-by-step explanation:
Hindsight bias explains the tendency of one to overestimate their ability to have predicted the unpredictable. It is like the "I knew it all along!" despite them not saying anything supporting that statement previously type of bias. For example, someone could take a random pop quiz and get a good grade. If they say, "Well I knew it was coming!", it is hindsight bias. You cannot predict a sudden pop quiz.
Overconfidence is the bias in which a person is more confident in the accuracy of their judgement than their judgement will be objectively. For example, you could state that you are 100% certain your favorite football team will win their next game. That is being overconfident.