In the game of blackjack, also known as twenty-one, the player and the dealer are dealt one card face-down and one card face-up. The object is to get as close as possible to the score 21, without exceeding that. Aces count either 1 or 11, face cards count 10, and all other cards count at their face value. The player can ask for more cards to be dealt to him, provided that he has not gone bust (exceeded 21) and lost. Getting 21 on the deal (an ace and a face card or 10) is called a blackjack. Suppose 4 decks of cards are shuffled together and dealt from. What is the probability the player gets a blackjack?