If you are using a fingertip bowling ball, each finger should go in the bowling to the first line In your finger. It should a little past your fingertips but that it. if you are using a house ball from the bowling alley, your fingers can go down to the second knuckle joint or half of your finger. Check out below for the pics on how far your fingers should go. The first picture is if your are using a fingertip bowling ball and the second picture is if you are using a house bowling ball from the bowling alley.