[asid61]

We let everyone in. Generally we have around 130+ applicants, and we split them up for trainings. By build season we usually end up with around ~80 people left, and by the end of build no more than ~40 are on the team. Those are just guesstimates, but we do lose a lot of people.
Generally if you hold basic training in how to use tools in the preseason, people will leave if they're not interested. For us, rookie retention is the issue as the trainings are of poor quality.