Task: Question Answering
Input (English): Sentence: Illegal pinning methods include using the ropes for leverage and hooking the opponent's clothing, which are therefore popular cheating methods for heels, unless certain stipulations make such an advantage legal. Such pins as these are rarely seen by the referee (as they have to see if their shoulders are down) and are subsequently often used by heels and on occasion by cheating faces to win matches. Even if it is noticed, it is rare for such an attempt to result in a disqualification (see below), and instead it simply results in nullification of the pin attempt, so the heel wrestler rarely has anything to lose for trying it, anyway. 
Question: How often are illegal pinning methods seen by the referee?
Output (English): Such pins as these are rarely seen by the referee