Looking at the opponent's previous choices, they've selected rock 4 times (rounds 2, 3, 5, 6) and paper twice, but never scissors. With their strong preference for rock, choosing paper gives me the best strategic advantage. While there's a risk they might switch to scissors (which they haven't played yet), the pattern suggests they're most comfortable with rock. Since I'm already ahead 3-1, making a calculated move based on their historical preference seems more logical than trying to guess a potential strategy change.