The TD is suppose to tell you before you tee off. Last year Dan Coffman said which tee pads to use and I believe the signs were covered with a trash bag to show you which ones were not in use. In prior years, Rick was TD and he also said which pads were suppose to be used. My guess though is long pads are used on 11 and 18 to prevent errant shots from 10 and 15 from interferring with drives. And then short pads used on 5, 13, 14. I've played every year though and do remember one year they didn't indicate what suppose to be used. Just ask before you get started.