How do you create a 4 player rotating bowling schedule with a 6 man roster?

League schedules can be found on the United States Bowling Congress' website at www.bowl.com. They have schedules for 4 to 48 teams.

Also, there is league software available on the market, such as CDE Software's Bowling League Secretary, that have the schedules built in.

In your case, you would use an 8 team schedule.