Based on pattern analysis, the opponent has frequently played scissors (including the last round) and paper. Since I'm ahead and only need to avoid losing, rock is a strategic choice that would beat scissors and only lose to paper. The opponent has used scissors in 4 out of 9 rounds, making rock a high-percentage play for the final round. Additionally, there appears to be a pattern where the opponent might respond to consecutive scissors plays (which I just did) with scissors again, which rock would defeat.