Here's why:
* Ace's Flexibility: An Ace is a very valuable card in Blackjack because it can be valued as either 1 or 11. This flexibility is crucial.
* Getting 21: If you have an Ace and another card totaling 10 (like a 10, Jack, Queen, or King), you have Blackjack (21) and automatically win (unless the dealer also has Blackjack).
* Staying Below 21: If your Ace is valued as 11 and your other card is 7, your total is 18. You could stand on 18 as it's a strong hand.
Important Note: You can only use the Ace as 11 if your total is 21 or less. If using 11 would put you over 21, the Ace automatically becomes a 1.