How can this be that no one has answered this already??? "One-and-One" or "One-Plus-One" is a free throw in basketball where if you make the basket on the first attempt, you earn a second throw. The initial attempt is awarded to the team that has suffered a certain number of non-shooting fouls. Obviously, in the example, they are doing practice (drilling) for the eventuality that a player will be allowed to do "One-and-One" in a game. In the text, you can see that the coach has made a slight change to the rules of one-and-one.