
The current record for the most players in a TCG event is currently held by Konami’s 100th Yu-Gi-Oh! Championship Series event in Long Beach in March of 2012, which drew 4,364 people (see "Guinness Certifies largest TCG Event"). For the Grand Prix Las Vegas to break the official record, not only will it have to draw more people (which sounds like a close thing, given the cap at 4,500), it will also have to have the attendance certified by Guinness as the new record. Fun to watch.