To effectively counter an opponent with a strong backhand loop, focus on disrupting their rhythm and forcing them out of their comfort zone. Employ a combination of varied spin and placement by targeting their forehand and body to create awkward angles, which can limit their ability to utilize their backhand effectively. Additionally, consider using shorter, low balls to make it difficult for them to generate the power required for their loop. Incorporating quick changes in pace and strategic use of spin variations can also keep them guessing, ultimately leading to openings for offensive shots where you can capitalize on their mistakes.