Hi, for a standard tournament how many rounds are played and how long is each? Thanks.

Depends on the number of people. You typically want to have 1 undefeated person after all the rounds are played. Games are between 60-75 minutes, and it's up to the TO to determine the time.

I've played as few as three and as many as five (and two more rounds to determine the champion).

An hour is pretty typical.

assume an average attendance of 10 players

With 8 players, three rounds will give you one undefeated player.

With 10-16, you'll need four rounds.

I also would highly recommend the TO for the tournament use the Cryodex program that is hosted on A Few Maneuvers. It makes running the tournament significantly easier.

I would also suggest that you move toward 75min rounds, 60 min rounds favors some builds more then others.