I'm playing in a Legacy tournament. My opponent has 6 cards in his hand to start his turn, and during his upkeep he decides to first cycle a Lonely Sandbar, and then to cast Brainstorm. He draws one for cycling, and then he draws 3 from Brainstorm, puts 2 back, then shuffles his hand around thinking about what to do next.
He decides to cast Bituminous Blast on my creature, and his cascade reveals the card Sylvan Library, which he casts.
We move on to his draw step, where Sylvan Library triggers, allowing my opponent to put back on top of his library any card that he has drawn this turn.
QUESTION 1: How can I obtain any level of satisfaction that the card he puts back is indeed one of the ones he drew this turn (for Question 1 purposes, assume neither of us realized this was a possibility when Brainstorm resolved)?
QUESTION 2: Next game, he casts Brainstorm during his upkeep, can I request that he openly track which cards he's drawn this turn? If not, why not?
QUESTON 3: A different opponent cast Brainstorm during a non-upkeep phase. Can I ask her to openly track which cards she's drawn this turn? If not, why not?
QUESTION 4: A different opponent draws his card for the turn. Can I ask him to track which cards he's drawn this turn when he, say, plays a land?
My argument for perhaps answering Question 3 in the affirmative is as follows: If "which cards are fresh," so to speak, is something I might need to know about, I should be entitled to track it so I know I am not being cheated. If I am entitled to track it in some contexts, nothing in the rules provides guidelines for differentiating those contexts from all others in which I might want to track the same information.
The rules handle a similar issue regarding Morphs by explicitly addressing the problem in the comp. rules.
"707.6. If you control multiple face-down spells or face-down permanents, you must ensure at all times that your face-down spells and permanents can be easily differentiated from each other. This includes, but is not limited to, knowing the order spells were cast, the order that face-down permanents entered the battlefield, which creature attacked last turn, and any other differences between face-down spells or permanents. Common methods for distinguishing between face-down objects include using counters or dice to mark the different objects, or clearly placing those objects in order on the table."
In a similar vein, all cards that search the library for a specific card type require that card to be revealed in order to avoid a "just trust me" result.
Rather than rely on a player's honor or a judge's presence, players are required to track openly what otherwise would be hidden information, where that information is necessary to maintaining a clear understanding of the gamestate. Why isn't there a similar rule for cards drawn, given that not allowing it to be tracked can lead a situation where I just have to trust my opponent?