Backup allies.
 

5.4.2. BACKUP TEAMS
Of the remaining eligible Teams, the highest seeded Teams (up to eight (8)) should remain on standby and be ready to play as a BACKUP TEAM. If a ROBOT from any ALLIANCE in an Elimination MATCH becomes inoperable, the ALLIANCE CAPTAIN may have the highest seeded TEAM still available join the ALLIANCE. The resulting ALLIANCE is then composed of four (4) Teams.
Has this always been a rule?

Re: Backup allies.
 

Yeah, for the past um, few years back. I don't know the original year that has been, but it's been there since at least 2010, probably longer.

Re: Backup allies.
 

Long as I've been involved in FIRST, seems like the next 8 are told to be ready just in case.

Re: Backup allies.
 

2005, IIRC. Something like that. (2006 for sure--I remember seeing backups that year.)

It's up to 8. Really, it depends on the FTA how many are told to be ready to play. Often, no more than 4 are given the notice; I remember a case where the top backup left--and the 2nd one was still there, and got a finalist out of it. Generally speaking, after QFs, no more than 4 will still be around--the rest will be allowed to pack up.

Re: Backup allies.
 

Being a lead que I have had to secure the backup teams. The most teams I have burned through was five at the 2012 Alamo regional. One was no where to be found and the other turned down the invitation. I have had teams openly turn down the role before. Most notably at the 2011 Midwest regional. A rookie team was the first backup and one of the robots on the opposing alliance to 111 ( I knew they were going to be World Champions the first second I saw them crush 1732 and 1625 in a match practically by themselves) so I went to go retrieve them. The team mostly consisted of a student and a teacher. A student from 1732 helped finish their robot. When I approached them to have them come to the field they declined immediately and packed up quickly. I remember telling Bill Miller who said "They can't leave!". I thought what are we going to do, Kick 'em out? I found the next backup who showed up, got stomped with their partners and got a nice shiny silver medal for their efforts.

Re: Backup allies.
 

I could be getting my years mixed up, but I believe that team did not have enough students to fill their drive team so students from 111 and 1732 (and maybe others) and filled out their drive team. I think they planned to decline being an alliance captain as it would have been very weird situation with having other teams be on their drive team, many of which were in the elimination matches. I am pretty sure that is why they declined being a backup.

The backup who did come in, 3197, did a very good job at pushing the tubes in the loading zones. But, 111 was too good that year...

Re: Backup allies.
 

I justs remember seeing the one student from 1732 hanging around their pits the whole time but obviously I was too busy to hang around to see who else was helping.
At the 2007 Buckeye regional there was a one student (no mentors) team. They had to borrow members of other teams to compete.