We do not have a selective team, but have discussed it with other teams. If we were to implement requirements they would probably go something like this
- After 1st or 2nd meeting give out simple "homework" for all students after each meeting. Something as simple as "you will receive an email from me this week. Respond to that email." You might be surprised how many students won't manage to reply.
- Each homework should be something basic like that, but should require effort. Something like, research any type of fastener and talk about 3 uses for it to the whole team.
- Homeworks completed (but not quality) should factor into who you accept. As long as they participate, they are welcome to come and be educated.
- Off season attendance higher than 50% of meetings. (It's great to have other extra-curriculars, but students who regularly miss meetings can end up so far behind that they are a detriment to the other students)
- Keep track of student participation and work ethic during meetings.
- At the start of the season (Aug / Sept.) announce a specific number of students that will be added to the team. This can be flexible in the end, but a hard and fast number makes it clear early.
That probably needs some tweaking but it's a good start. The key for us would be that we aren't barring people based on aptitude or "ability", we are barring them based on attitude and willingness to work as a team. Those are the qualities that can make or break a team. And students without them often negatively effect the whole team.