Number of Cards in a Deck

[jamestosetti]

I was reading about format rules on WOTC's website, and I saw that there is no maximum number of cards for a Vintage deck as long as you can shuffle your deck on your own. Is this true? I was not aware of this.

[TVand]

This is true (of any constructed format).  In fact, Battle of Wits decks (which have to be around 250 cards) have been played competitively (to varying levels of success) in Standard, Extended, and Legacy throughout the years.