Haha, yep, to prevent injury (and to help with tracking). Dogs will twist and turn to try and catch a disc and if you throw right at their face, they don't have enough time to plan and execute the right movement.. it becomes unpredictable and unsafe then. Eventually there will be moves you learn that require you to throw a disc right at them, but it's usually placed above them, so they can move to the disc still. There are some good youtube videos that teach rollers. Practice them without your dogs first, then introduce your dogs after you feel confident about them. Good luck!