I use two 430 EX II's in the corners of the gym aimed above the players heads and toward the top of the key. Set to 50mm on 1/2 power.
How long have you been using off camera light? I used speedlights for a year and then started using my Alien Bees B800 monolights 2 years ago and have never looked back. Best thing I ever did.
Here is a gallery of one of my most recent games: http://apeximaging.zenfolio.com/p343683002