Do you always need to keep track of what cards have been drawn in a turn?
The reason I ask is because of Sylvan Library. While it's on the battlefield it's pretty obvious that you have to do it because you can put back any card you've drawn that turn back on top of your library.
But what about when Sylvan Library is not on the battlefield? I can't find any rules about it. As far as I have known people are are allowed to shuffle the cards in their hand and I've seen it happen a lot as a tactic to confuse your opponent. But what about the following corner case situation:
- You have a Vedalken Orrery on the battlefield and no Sylvan Library
- In you upkeep you cast some spells that let you draw some cards
- You shuffle your hand a bit
- Still in your upkeep you cast Sylvan Library
- Sylvan Library triggers in your draw step
Now what? you have no way of telling what cards you have drawn in your turn. This seems to suggest that at all time you need to set the cards you've drawn aside. Can anyone clarify this?