"Dealer's Bust" side bets in blackjack involve betting on the chance that the dealer will bust by exceeding 21. Effective strategies for these bets hinge on understanding probabilities and the dealer's upcard, with players more likely to bet on a bust when the dealer shows weak cards like 4, 5, or 6. Evaluating the deck's composition can also aid in decision-making, as a higher proportion of low cards increases the bust potential.