LAS VEGAS — The man running the World Series of Poker says early buy-ins are up and registration rules have changed as officials try to avoid shutting players out of the richest event in poker.

Tournament Director Jack Effel said Tuesday that more players than ever before have registered early for this year's $10,000 buy-in no-limit Texas Hold 'em main event in Las Vegas.

The starting field is split across four days in July.

Nearly 6,500 players entered last year, but about 500 players were turned away when the tournament sold out slots on the last opening day. That's usually the most popular day to start.

Effel says officials will stop registering players for days that get too full, and force players to pick another time to start.