There is no definitive answer to this question as it depends on the specific rules of a particular casino. In general, though, casinos usually require dealers to hit on 17 in blackjack in order to keep the game going.
Some casinos allow dealers to use other strategies, such as splitting cards, in order to improve their chances of winning. However, hitting on 17 is generally considered the most effective way to play the game.
A dealer who fails to hit on 17 can often lose money for his or her casino. This is because players are more likely to hit on 17 when they are playing with a dealer who does not hit on that number.
