I definitely agree that 4th picks should happen. Teams that are good enough to be picked as a 4th robot are more deserving of a chance at elims than the team that happened to seed high (since we all know seeding has very little to do with robot performance) and I'm sure that alliances would prefer to choose their own back up robot.
Regarding location and fields, there is more than enough space in the st louis arena for 8 fields (specifically the giant empty space in the middle), the issue is arrangement and volunteers. Twice as many fields translates to nearly twice as many volunteers. The only way to place twice as many fields in the arena is to either arrange them length wise, or put one behind the other. Neither of which is spectator friendly unless you put bleachers in the middle of the stadium facing out. The other issue is scouting. Scouting would become almost completely impossible for most teams as they wouldn't have enough team members to scout 2 fields at once.
After thinking it over, I really don't think it it's a good idea to move to 2 fields per division. In terms of exclusivity I don't think there is a percentage of teams that can really be set to attend CMP. The number of teams attending is really limited by the arena capabilities. There should be no more than 100 teams per division to ensure an adequate number of matches (less than 10 matches per team is undesirable), and you can't add divisions in small increments, you essentially need to add teams at a rate of 100 per addition to maintain the current division layout. With how CMP is run right now I can't see there being any more (or much less) than 400 teams without a major overhaul. I think FRC is staying as is for a while but I definitely think the largest improvement we will see is the increasing prevalence of districts as that seems to be the best system to determine CMP eligiblity.
Districts can't get here soon enough
