BG Tavern Card Pool Mechanic Theory?

I am wondering if the Tavern’s pool of cards has a finite limit of each race type per round and overall. Making the reason why sometimes you might get any of certain types and an overload of other types.

I am wondering because there will be times I will not see a specific card at all even when I make it to the top 4. Other times I will see lots of them.

Yes, the tips even say as much, There are only 3 copies of any given T6 minion and at various times where they added mechanics like magnetic minions on death rattle it has been possible to pull every single magnetic minion and the death rattle gives nothing.

Having said that sometimes you can go 10 rounds at t6 and just not see a minion.