In Blackjack, several key probability concepts and principles come into play. First, understanding the odds of drawing specific cards is crucial, as players need to evaluate the likelihood of busting (exceeding 21) based on their hand total and the dealer's upcard. Players also consider the effects of card counting, which involves tracking the ratio of high to low cards remaining in the deck to inform betting and playing strategies. The concept of expected value plays a significant role in making decisions, as players weigh the potential outcomes of different actions—such as hitting, standing, or doubling down—against their probabilities.