In a sequential game, a player observes their opponent's move and chooses their response based on that observation. What is the most likely reason that the observing player achieves a higher payoff by choosing their strategy after observing the first player's action?

When the second player sees the first player’s move, they can choose a response that is the best reply to that specific action instead of guessing. This conditional strategy lets them exploit the first player’s choice, often picking a payoff‑maximizing move that the first player cannot anticipate. Because the first player must commit to a strategy before seeing the second player’s reaction, they cannot adjust to the second player’s best reply. Consequently, the observing player can consistently secure a higher payoff by tailoring their move to the opponent’s action. For example, if the first player chooses “A” and the best reply is “B” that gives the second player a higher payoff, the second player will choose “B” after seeing “A.