The punch cards they hand out to you at sign up are attached to the left side of your handlebar and at some point through the lap, they have a checkpoint where the punchers will punch a hole. So in theory you will get a hole punched for each lap. At the end of the race, all the punch cards are cut off the bar and then used by scoring to verify that you actually did the number of laps that the bar code scanner says. The intent is to make it harder to cut the track. If scoring says you did 4 laps, but you only have 3 holes in the punch card, you only get credit for 3 laps. It's not fool proof of course, and they have other ways to root out cheaters that try and cut the course by watching for "short laps," but that's the NCHSA system. Mainly, it keeps the honest people honest.
Here I am going through the check-point: