Chuck Norris World Combat League

I particularly like the battle zone

The no-rope ring (sometimes referred by fans as “the pit”) is a circle which is 27 feet in diameter, of which the inner 24 feet is colored blue. The next 3 feet is yellow, which is the caution area. When the fighter gets to the yellow area, he knows he’s getting close to stepping out-of-bounds. The last edge of the ring is the red zone, which features a 30-degree upward angle. When a fighter steps on the red area, he’s stepping up slightly, letting him know he’s out-of-bounds.