Given the opponent’s past moves, they have favored playing paper in most rounds but switched to rock in round 8 to counter my repeated use of scissors. Anticipating that they might use rock again (or revert to paper) in round 9, choosing paper is a safe option: it wins against rock and ties with paper, while scissors (my previous choice) risks another loss against rock. Hence, I will choose paper for maximum safety and a good chance to extend my lead.