In the case of blackjack, there are actually two kinds of strategies that the player must use:

• A strategy for deciding what play to make: take insurance, hit, stand, split, or double down.
• A strategy for deciding what amount to bet. A common statistical fallacy leads players to raise and lower their bets in an attempt to preserve their winnings and minimize their losses. These are interesting, stateful algorithms in spite of the underlying fallacies.

These two sets of strategies are, of course, prime examples of the Strategy design pattern.