Looking at the previous rounds, I notice the opponent has shown a pattern of alternating between rock and scissors (they haven't played paper at all). In rounds 1, 3, and 5, they played rock, scissors, and scissors. In rounds 2, 4, and 6, they played scissors, rock, and rock. For odd-numbered rounds like round 7, they've favored scissors in the past. If they continue this pattern, rock would be my best choice to counter their likely scissors play. Even if they switch to rock, I'll tie rather than lose, which helps maintain my current lead in the match.