Ban cavalry.
But seriously, cav are great; they can be great support when they know what they're doing and how to do it, and they're formidible foes when they know what they're doing and how to do it. When they suck, you can always accidentally dehorse them when they try to steal your kill, on a straight trajectory toward you, instead of your opponent, guaranteeing your death via teambump. Also, poor cavalry players are generally great padding for kdr, which is roughly equivalent to your penis size.