Random can be weird.
I’ve lost count of how many bg’s there are but I used 7.
So here is a simulation using a random number generator for 10 nights of 7 bgs per night.
[4, 7, 4, 1, 5, 2, 3]
[5, 7, 2, 7, 6, 7, 4]
[2, 1, 4, 5, 2, 7, 5]
[4, 4, 1, 1, 6, 4, 5]
[4, 4, 3, 2, 6, 1, 6]
[1, 1, 6, 1, 1, 4, 4]
[1, 6, 2, 2, 4, 1, 6]
[6, 3, 4, 4, 7, 5, 4]
[2, 5, 2, 7, 5, 2, 3]
[3, 3, 3, 6, 5, 1, 5]
You can see that it is quite rare to have no duplicates during even a short session. In fact there a few with triplets in there.
I’m not an expert in probability, but i’m pretty sure that it’s more likely to get a duplicate of something than it is to get none.
I think that folks are expecting something like a rotation with dup protection whereas in reality it’s just random.
/regards