The "dealer bust" strategy in blackjack focuses on capitalizing on the dealer’s likelihood of busting when they have a weak upcard, such as 4, 5, or 6. When the dealer shows a weak card, the goal is to minimize risk by standing on your hand, as the dealer is more likely to go over 21 due to the cards they are required to draw. This approach doesn't focus on trying to get 21, but rather on letting the dealer make mistakes. However, when the dealer shows a strong card like a 10 or Ace, the strategy shifts to standard basic strategy, as the chances of the dealer busting are lower. The dealer bust strategy complements basic strategy by advising when to avoid risky moves and take advantage of the dealer's potential weaknesses.