Rotors work best for large areas (over 50 ft) without a lot of complicated lawn area shapes. The only time they work well in smaller yards is in unobstructed rectangular areas that happen to measure at an even multiple of the radius distance. For example, if the rotor throws water 30 ft, they can be used in a square area 30 ft on a side, or an area that is 30 ft by 60 ft. They are ideal for very large lawns of a half acre or more. Spray sprinklers do a better job of watering small yards or yards with lots of obstructions such as trees and bushes, walls, fences, etc.
Greener, More Efficient Ways to Grow Your Lawn