What is a stun shot?
Stun means pure sliding, where there is no topspin or bottom spin. With a stun shot, the CB has no top or bottom spin when it hits the OB. For a straight in stun shot, the CB stops in place and transfers all of its energy to the OB. This is called a stop shot. With any other stun shot, with a cut angle, the CB heads in the tangent-line direction, regardless of the cut angle (see the 90° rule). A stun shot is sometimes called a “stop shot at an angle.”
With a stun shot, the CB must be struck below center. The bottom spin will wear off (this is called drag) on the way to the OB. The farther the CB is from the OB, the lower and/or faster you need to strike the CB to prevent the CB from losing the bottom spin and starting to developing forward roll before hitting the OB. If the CB has any topspin when it hits the OB, the CB will follow forward. Here’s a slow motion video showing how drag works with a stop shot:
Here’s an example stun shot:
Here’s a good drill for practicing stun shots from Vol. II of the Billiard University (BU) Instructional video series:
For more information, see “Billiard University (BU) – Part V: Stun Shots” (BD, December, 2013).
The following video illustrates stop, stun back, and stun forward shot variations and shows how you can use pages of a book to help ensure accurate tip contact heights on the CB:
from Patrick Johnson: