Methods, systems, and computer readable media for controlling delivery of content are provided. In some embodiments, a system for controlling delivery of content is provided. The system includes processing circuitry configured to: transmit, to a server, a plurality of requests for blocks of the content; while at least some of the plurality of requests are still outstanding: detect a change of a service characteristic of a connection between the system and the server; determine a preferred number of outstanding requests; and cancel at least some of the requests from the plurality that are still outstanding based on the preferred number and a count of the requests from the plurality that are still outstanding.