Our Monday night mixed league does not allow roving substitutes for two reasons ... 1 - we had professional subs who cluttered up the settee area every week trying to get in three free games of bowling; and 2 - we had two subs the first year who chose the teams they'd bowl for in an attempt to see how they could manipulate the standings.
Instead of subs, we have expanded rosters. Once someone is on your roster, they can only bowl for your team. If someone wants to move to a different team it must be submitted to the board for a vote. This, by the way, has never happened, and we are in our third year of the expanded roster rule.
Deb