“The Mashgiach decides what the geder of lateness to shiur is, not you.” (Weiser)

“If a bochur has no geder, he is likely to be kicked out.” (Weiser)

"the point is so that you arent bombarded with a nisayon, and that theres an extra geder. suppose you happened across a site featuring pictures of scantily clad women, you would probably be more inclined to investigate further than if you had never happened across that site in the first place." (source)