Your team won't follow your rules. But they will follow rules made by the team captains.
That was the conclusion Dr. Amber Warners reached when she researched underage drinking on college sports teams. It didn't matter how many times a coach told her team not to drink. They did anyway. It didn't matter if a coach implemented an alcohol policy. Athletes would break it.
But the way team captains used alcohol mattered a lot. If the captains misused alcohol, the entire team did. And vice versa, if captains were responsible, so was the rest of the team.
Warners told me a few months ago that she no longer makes rules for her team. She discusses it with the captains first, then the captains make the rules.
It matters a lot who your captains are, because for better or worse, athletes will look to their peers for information about how to behave.