Sounds like you are wanting to change POOL configurations and that is not doable eg, you can't change a Single Elimination Pool into a Double Elimination pool after the pool has been created (and started).
Posting this so that if OTHERS are reading that do not understand what a Survivor Pool is, it might help them better understand.
A Strike is something that a player receives when they make an incorrect pick for that week. When a player makes an incorrect pick, they get a strike. If the pool is single elimination, that player is eliminated from the pool. If the pool is double or triple elimination, they are still "alive" and move onto the next week. If they get a 2nd strike and the pool is a double elimination pool, they are eliminated, however, its the pool is a triple elimination pool, they are still alive and move onto the next week and are alive until they another wrong pick.
Adding more teams to a Sport has no effect on whether a Survivor Pool is Single, Double or Triple elimination.
Single Elimination Pool
Player A joins a single elimination survivor pool
- Week 1 - Correct pick, moves on to week 2
- Week 2 - Correct pick, moves on to week 3
- Week 3 - Correct pick, moves on to week 4
- Week 4 - Incorrect pick, receives Strike #1, is eliminated from the pool
Player B joins a single elimination survivor pool
- Week 1 - Correct pick, moves on to week 2
- Week 2 - Correct pick, moves on to week 3
- Week 3 - Correct pick, moves on to week 4
- Week 4 - Correct pick, moves on to week 5
- Week 5 - Incorrect pick, receives Strike #1, is eliminated from the pool
Player C joins a single elimination survivor pool
- Week 1 - Correct pick, moves on to week 2
- Week 2 - Correct pick, moves on to week 3
- Week 3 - Correct pick, moves on to week 4
- Week 4 - Correct pick, moves on to week 5
- Week 5 - Correct pick, is the only player left, is the WINNER of the pool
Double Elimination Pool
Player A joins a double elimination survivor pool
- Week 1 - Correct pick, moves on to week 2
- Week 2 - Incorrect pick, receives Strike #1, moves on to week 3
- Week 3 - Correct pick, moves on to week 4
- Week 4 - Incorrect pick, receives Strike #2, is eliminated from the pool
Player B joins a double elimination survivor pool
- Week 1 - Incorrect pick, receives Strike #1, moves on to week 2
- Week 2 - Correct pick, moves on to week 3
- Week 3 - Correct pick, moves on to week 4
- Week 4 - Correct pick, moves on to week 5
- Week 5 - Incorrect pick, receives Strike #2, is eliminated from the pool
Player C joins a double elimination survivor pool
- Week 1 - Correct pick, moves on to week 2
- Week 2 - Correct pick, moves on to week 3
- Week 3 - Incorrect pick, receives Strike #1, moves on to week 4
- Week 4 - Correct pick, moves on to week 5
- Week 5 - Correct pick, is the only player left, is the WINNER of the pool