It’s finally here – what could potentially be the greatest tournament poker spectacle of all time is about to take place at the World Series of Poker. Sunday will see the start of the Big One for One Drop, the $1 million buy-in poker tournament that will shatter records for tournament poker, while also raising serious money for an important charity initiative.The tournament is now officially sold out, having reached the cap of 48 players. However, two of the seats that were guaranteed to satellite participants (one in Las Vegas, and one as part of an international VIP program from MGM Resorts) are still to be awarded at the time of this writing.The list of players participating includes not only the stars of live and online poker, but also a number of ultra-wealthy businessmen from around the world. Venture capitalists, casino owners and hedge fund managers will be lined up against some of the toughest players around in a battle for a first prize of $18.3 million. The top nine players will take home prizes, with the minimum cash being worth over $1.1 million.The tournament isn’t just about big prizes, though. It will also raise more than $5 million for the One Drop Foundation, a charity that supports access to safe water around the world. The tournament is not raked, but 11.1% of each entry will go to the charity.For poker fans, there will be plenty of familiar faces, as more than half the field is made up of professional poker players. Participants include Tom Dwan, Jonathan Duhamel, Antonio Esfandiari, Bertrand “ElkY” Grospellier, Phil Ivey, Ben Lamb, Jason Mercier, Michael Mizrachi, Daniel Negreanu, Erik Seidel, Mike Sexton, and many other top pros.The tournament is scheduled for three days. All of the action can be followed online at WSOP.com, while the third and final day will be televised nearly live on some television networks, such as ESPN in the United States.