Vyvyan Basterd
Adventurer
Our games run in 4 1/2 chunks (really 4 hours and some paperwork) starting at 8am, 1pm, and 7pm each day (just 8am on Sunday). So if your game starts at 9am and wraps up at 1pm you'll find tons of fill-ins from people showing up late but still having something to play at 1pm. If your game runs to 3pm you'll lose players because it will crossover into another game they have scheduled.
It's been a while since I've made it to GenCon. Has the Con disposed of set times slots in general? Or does the RPGA area run on a different schedule. It seems like it would cause a nightmare to register if the whole Con didn't follow the "4 set slots per day (2 on Sunday)" schedule of the past.