Looking at our previous rounds, I've gone paper-rock-paper, potentially establishing a pattern my opponent might recognize. After our paper-paper tie in round 3, my opponent might expect me to return to rock (continuing my alternating pattern) and could choose paper to counter. Alternatively, they might stick with paper thinking it worked well enough last round. Scissors would be effective against either of these paper scenarios. Since I'm leading 2-0, I can afford a calculated risk with scissors for this round.