A few Words for the River Overbet
First of all a little vocabulary, the River is the fifth and final card to appear on the Flop. It is this card that will most often determine the winner of the round. At this point in the game you know exactly what is in your hand. You are therefore able to think of a strategy for the last betting round and play accordingly.
What is your hand worth at the River?
On the River, either you think you have the best hand, or you think your opponent (s) have the best hands, or you think your hand is average but has a chance of winning the round with a good strategy. In the last two cases the Bluff will often come into play.
Very often, the River is played in Heads-Up, that is to say with two players alone, because players will have folded before, before the Flop, at the time of the Flop ...