The present invention determines which network devices are likely to have a positive result in engagements with terminal devices. A server can obtain data about network devices with respect to the communication session with a network site. Then the server can use rules to define a set of network devices that are eligible to interact or communicate with a terminal device. The server can connect to the network devices as randomly as possible. Terminal devices can initiate engagements with network devices. The server can detect characteristics in the interaction of engagements that have positive results. The server generates an evaluation protocol based on the characteristics, to assign new network devices a parameter representing how close the new network device conforms to the evaluation protocol. The parameter is used by the system in real-time to inform terminal devices as to which network devices to connect to and in what order.