I count the holes. I take a lot of different folks riding, and I tell them that they must remember their number--that is their job. I remember my numbers on my different saddles. Usually where the stirrups go on my saddles is already quite dark and marked . . . but English stirrup leathers stretch, so sometimes there is a "dark and marked" place on several different numbers. Best to remember what YOUR number is on each saddle. If you are awful at remembering numbers like I am, you can associate it with something special you did, or your child's age when something important happened, like #12, in 2012, we went to Bahamas. Or #5, when my daughter was 5, we moved to this house.