Since I won with paper in the previous round, my opponent might expect me to use paper again or switch to scissors. If they anticipate I'll use paper again, they might counter with scissors. By choosing rock, I can counter their potential scissors play. Additionally, if they're trying to be unpredictable and switch to paper (expecting me to play rock), this introduces a balanced risk. This move disrupts any simple pattern recognition while providing a tactical counter to the most likely opponent response.