def check_hand_bust(hand):
	""" Check if a hand has busted and return boolean."""
	sum = 0
	ace = False
	for card in hand:
		if card.value == 11:
			ace = True
		sum = sum + card.value
		if sum > 21:
			if ace:
				sum = sum - 10
				ace = False
			else:
				return True
	return False