I'm choosing rock for the final round based on analysis of previous patterns. My opponent has shown a tendency to choose scissors when I've won with paper in the previous round (as seen in rounds 2 and 8 where I won with scissors and rock respectively after winning with paper). Since I won round 9 with paper, there's a possibility the opponent might choose scissors to counter an expected paper play, making rock the optimal choice. Additionally, rock has been successful for me in previous rounds (3 and 8), and this selection maintains an equal distribution of my choices across the game (rock: 3 times, paper: 3 times, scissors: 4 times including this choice).