As defined in the NFHS rule book -
Rule 4 Section 25 Articles 1 and 2:
Art. 1... Opponents have their hands so firmly on the ball that control cannot be obtained without undue roughness.
Art. 2... An opponent places his/her hand(s) on the ball and prevents an airborne player from throwing the ball or releasing it on a try.
In 1 it seems as if hands and opponents (both plural) illustrate the idea that there needs to be four total hands? How does one define undue roughness for middle schoolers?