Systems and methods of a balancing data requests over a computer network are provided. The system can receive a request for content to be rendered in a content slot on a computing device. The content slot can be coded with a default timer value. The system can execute a real-time content selection process to identify content items that each have a magnitude. The system can determine a timer value based on the magnitudes, and transmit the timer value to the computing device to override the default timer value to cause the computing device to replace a first content item rendered in the content slot upon expiration of the timer.