During late game situations as a player gets tired they are going to have to really lock in mentally and learn to hit shots when they are tired. It is a different feel than when the player has fresh legs at the beginning of a game. That is why it is important to practice and do some basketball shooting drills that are going to make the player hit shots when they are tired.
The 20 point partner shooting drill is going to help the player work on several different shots, but it is also a conditioning drill. That means as the drill continues to go on they will get tired, and this will help simulate a late game situation. Another great thing about basketball drills like this is that they add a competition aspect to the drill. Because the player is being graded on how many shots they make during the drill it will hopefully help to simulate a little bit of game pressure.