There is a relatively new addition to our software that takes historical numbers of gate checked bags based on day of week, equipment, dptr time, and route, along with load booked and estimates the numbers that will need to be checked based on overhead space. It's still far from perfect, but it isn't terrible (I think it needs more data to be more accurate.) Things such as large school groups with only backpacks throw it off. Clearly on a full airbus to LGA, the numbers are far higher than on a widebody or a flight to any place other than LGA.