at the pub the otherday we were discussing the game of snap. i suggested that snap should be played with two decks of cards, otherwise you could never get a true 'snap'... i was quickly ridiculed: i won the derision and contempt of my peers. "such a game would take too long!" they scoffed.
i wrote a script to prove my point (i know this could be done analytically, but why think when a machine can tell you the answer?) - simulating how long it would take to get the first 'snap' in a 104-card game between two decks. the answer is, it takes ~35 tries (if you discount the number of times the game ends without a snap -- about 45% of the time). if it takes about 1sec per try, then this is only half a minute. not long at all in my opinion. the game will end quickly, because on average you lose most of the deck on the first snap. thus, two-deck snap is actually a pretty fast way to play.