[header] How to box out in basketball [title] Ensure a shot has been taken. [step] Often, watching an opponent pass the ball with peripheral vision can be mistaken for a shot, particularly if it is a lob pass across the court. A common, helpful method of determining if a shot has been taken is to listen for your teammates yelling, " shot ". 
[substeps] If you see a shot taken, yell " shot " yourself so others can hear you. If you move to box out with your back turned, the player you're guarding can easily cut past you to the basket.