Sentence:  The person performing the theatrics, the "<WSD>eyeballer</WSD>," is an independent contractor of sorts, hired by you to play nearby and keep an eye on the action at your table; when things get hairy, he's to shark your opponent from afar, all the while making it look innocuous and wholly unintentional. 
Meaning of the word marked with <WSD> tags:  A secret accomplice who surreptitiously watches the competition and interferes by causing a distraction to prevent the opponent from getting a good shot.