Ok one more deck then we are all done ok?
TIME KILLER
20x Plateau
20x Lightning Bolts
20x Sharazads
Ok... done now.
think about it, 60 card decks, if you draw a single card you have a 6% chance of picking 1 of 4 copies of the same card, now instead draw 7 you have roughly a ~~45% chance of drawing that card. Now lets acompany for turns til used. This has been changing as of rescently with more meta game but lets say about 7 draws is what you would normally get. ~~90% chance of drawing 1 of the 4 copies of that card in your deck, so you can base a deck around a single card a draw it ~~90% of the time.
If you change that to 3 your chances go low, very low fast, and if you you increase the numbers, the decks have little to no varitey in them, if the deck min size changed lower I could see 3 working about as well as four. More that 4 with all the different searchers etc, that would just stink to play against...