This is how it was explained to me. There are two types of 10 pin leaves: weak and solid/ringing. The weak 10 pin occurs when the 6 pin falls into the channel. This is a result of not hitting the pocket solid, but rather hit it a little light. The solid /ringing occurs when the ball hits the pocket and the 6 pin flies around the neck of the 10 pin. This occurs when the ball hits with to much power and/or the wrong entry angle into the pocket and sends the pins air-born. The last few years I have seen more pocket hit 7-10's and a few 5-7-10's.