(taken from MrWizard's post at TestYourMight.com
Evolution 2011 is a Bring-Your-Own-Controller event. We provide the consoles, games, monitors and speakers for every game station, but it's up to the players to bring the controller they plan to play. This year we are restricting the controllers players are allowed to bring to ensure fair play and guarantee the integrity of the results.
How Wireless Controllers Work
All EVO games will be run on the Playstation 3. The Playstation 3 Dual Shock and Sixaxis controllers are both wireless devices. Plugging your controller into a PS3 for the first time pairs your controller to that Playstation. This pairing will be remembered by the Playstation until you sync your controller to another Playstation. We have found no reliable workaround to remove this pairing (1).
Since there's no easy way to unpair a controller from a Playstation 3, any player who had previously played on a game console may accidently interfer with another game in progress. Consider the following scenario
1) Players A and B sync their controllers to the game station.
2) After they finish their game, Players A and B turn off their controllers.
3) Even though their controllers are turned off, the Playstation still remember that they are paired.
4) Players C and D sync their controllers and begin the next game.
5) Player A turns on his controller and hits the home button.
6) Since he hasn't yet synced his controller to the new station, hitting the home button will interrupt the game played by Players C and D.
There are a million different ways this can happen. For example:
1) A player eliminated from the tournament puts his controller in his backpack. While he's walking, some item in his backpack accidently bumps the home button, interrupting a game in progress.
2) A player finishes his semi-final match and turns off his controller. 15 minutes later he is called for his match in the finals of the winners bracket. While syncing his controller to the new Playstation, he accidently hits the home button while before his USB cord is plugged in, interrupting the semi-finals of the loser's bracket happening on the console he just left.
3) A sore loser eliminated from the tournament maliciously presses his home button to interrupt matches.
4) A player notices that is friend is about to lose a match on a console that he had just played on. He decides to "save" his friend by pressing the home button, forcing a replay of the round.
While some of these may sound far-fetched, each of these scenarios has happened at past EVO events. Some have occurred multiple times. In order to ensure the integrity of future events, we are not allowing players to use controllers which pair themselves with Playstations.
1) Fight Sticks. To our knowledge, all fightsticks made by Hori and MadCatz use a wired connection and do not pair themselves to the PlayStation. They are all allowed.
2) MadCatz Fightpads. MadCatz Fightpad use a bluetooth USB dongle to pair the pad to the dongle. Since they do not create a paring between the pad and the Playstation 3, they are allowed.
3) All PS2 Controllers used with a PS2/PS3 convertor. Dualshock 2 or other PS2 controllers used with a converter box to convert them to PS3 controllers are allowed. For players accustomed to using a PS3 controller, this is your best option.
Specifically Banned Controllers
1) The Sixaxis and Dualshock 3 controllers designed for use on the Playstation 3 are specifically banned. These controllers have been the source of all of our problems in the past. We realize you can make these controllers "tournament friendly" by opening them and removing the batter, but we have no good way to enforce that rule at the scale EVO must operate on to finish on-time.