There is a link on the link leger.Most people I know take a six inch length of line fold it over the mainline and keep it in place with the ssg.This is stopped from running down to the hook by another ssg.The advantages over ssg put directly on the main line is the ssg should slide of if the snag up, and the rig is infinitley adjustable.In other words you can adjust the length of the hook length and remove or replace ssg without risk of damage to the mainline.What I have described is the most basic link leger set up, there are others that use swivels or leger beads but once you have set up the version as above I am sure you will be able to modify it if you think it needs it.