Team 114 does have tryouts for the driver position, but seniors usually get priority. They are the ones who have been with the team the longest and have (usually) the most maturity. The way we see it, Juniors and down have at least another year so we should let the seniors shine. We also usually have a programmer in the group, be it coach or arm control, so they can check out how the autonomous mode is.
As for the human player, you should just pick by skill. I was the human player last year because I was the only guy that could shoot reasonably. This year you should look for a human player that is quick, sharp and won't let the pressure make him jump to early or misplace the tetra.
This year especially, the coach should be a good listener, but able to speak out when it is the right time. Maturity would help too
