Dana White

(WWE), the world's biggest sports entertainment company and the top mixed martial arts promotion (UFC) completed their merger.

The competitors stand rigidly upright with their hands behind their backs, waiting to absorb a brutal slap to the face.

The state commission that regulates slap fighting — in which opponents take turns striking each other in the face — attempted Wednesday to address a critical question for the budding sport: What constitutes a legal slap?