1. A playback device configured to perform multiphase adaptive bitrate streaming by requesting portions of encoded media from a plurality of alternative streams of encoded media that are encoded at different maximum bitrates in response to changes in streaming conditions, the playback device comprising: a processor configured, via a client application, to request portions of files from a remote server; wherein the client application further configures the processor to: commence streaming of the encoded media in a first operational phase utilizing a first set of stream switching conditions by requesting portions of the encoded media from one of the plurality of alternative streams; measure streaming conditions; when a first set of stream switching conditions is satisfied in the first operational phase, requesting portions of the encoded media from another of the plurality of alternative streams; when at least one phase transition criterion is satisfied, transitioning to a second operational phase utilizing a second set of stream switching conditions; and when the second set of stream switching conditions is satisfied in the second operational phase, requesting portions of the encoded media from another of the plurality of alternative streams.