I mentioned all of this in another thread.
The perennial question. The conundrum of conundrums.
The answer you get till depend on who is giving it to you.
Most DOCs will publically say players are chosen on merit. That is true to some extent. However, what they deliberately fail to tell you is how they define "merit".
Most, if not all, Selection Panels will say the same thing as the DOC because it is in their interest to do so.
IME, players aren't competiting for a spot on the team per se. They are actually competing for a spot for a particular position on a team. So, if there are several potential Point Guards, they will be competiting against each other for the limited PG positions. They would not be considered for other positions on the team.
During Tryouts, the smart players aren't looking to compete against everyone else at the Tryouts. They just look to compete against players of similar height, size, etc.
Afaic, the Associations I've experienced tend to pick 80% of the players for their 1st team prior to Tryouts. In the older VJBL groups, these players and / or their parents usually have a history with the Association. So the remainimg players are usually competiting for three or four spots. Depending on the desired team structure, many players outside of the preferred group may end up competiting for one spot on the 1st team. Many of those players will end up in the 2nd team if they are future prospects for the 1st team in the following season. Otherwise, they are likely to end up in the 3rds of lower depending on the number of players at Tryouts.
It also helps if a player is quite tall. They tend to be the first to be noticed and picked for teams, especially the ones with athletic ability.