Wiktionary
courtsiding
n. The transmission of information from a sports event (especially a tennis match) for the purpose of obtaining a betting advantage
Wikipedia
Courtsiding
Courtsiding is the practice of transmitting information from sporting events for the purpose of gambling, or of placing bets directly from a sporting event. It has been observed as occurring most prominently, although not exclusively, in tennis. It arises as a result of the delay between live action and digital television broadcasts.