This is the final round, and the score is tied 3-3. Looking at the previous rounds, my opponent has chosen paper 4 times, scissors 3 times, and rock 2 times. Given that my opponent favors paper historically, they might expect me to play scissors to counter their paper tendency. To counter this anticipation, I'll play rock which would beat their scissors. Additionally, my opponent might notice I've never played the same move twice in a row, and since I played paper in round 9, they might expect scissors or rock from me. If they're trying to be unpredictable in this final round, they might avoid their most common choice (paper) and play scissors instead. Rock would be the optimal counter to this potential strategy.