Hi Susan,
If you follow the schedules link near the top of this page, and then click 16 items and 'Whist', you will get a schedule with 15 rounds. I think you can use this as the basis of your marathon. The player number who hosts can be the same as the round number. Finally you can add any 16th round you like - if you were keeping score over the first 15 weeks, then perhaps have the best 4 players on table 1, the next best 4 players on table 2, etc.
Hope that helps,
Ian.
