Lots of players don’t realize that they are entitled to the vertical space above them when the disc is in the air. And for those who do know about the principle of verticality, many aren’t always clear on how to know if a foul has been committed.
First, it’s important to understand what the principle of verticality is and then it’s important to understand how to interpret the rule in order to determine if a foul has been committed.
According to the USA Ultimate 11th Edition Rules,
b. Receiving Fouls: