There are so many guaranteed spots at the regional, Mid East Red Bud has 7 per regular class. Only 4 guaranteed sent in their money this year...... so of the 42 rider gate, 3 spots are open for "alternates". Alternates to not have to be from the same region as the region that doesn't have full participation as there is a formula for Rider Point Value (RPV) for alternates to give the alternates who would be the fastest a chance to get in. The formula basically takes your overall finish divided by the total # of riders at your regional, and gives you the percent of riders that you beat as your RPV number. The highest RPV #'s are the ones that get the spots that are left open from the riders that do not take the guaranteed spots. In my case, my RPV in Vet B/C was 71.795 for beating 71.795 percent of the class at Red Bud and finishing in 11th place overall out of 39 riders. The more riders at your regional the better off you are for RPV values because if I had finished 11th at North Central Regional in Illinois, my RPV would have been 64.516 since only 31 riders showed up to that regional. Based on the numbers, and sign ups, I was going to be either the 41st or 42nd rider into the event this year based on sign ups of the guaranteed spots....... A little complex, but you can figure it out off of the info you can get from MX Sports web site.