A method for dynamically delivering variable bit rate media content across a network to a plurality of client systems, the method comprising: receiving, at a server, a request for a media content from a client system of the plurality of client systems; delivering, by the server, portions of the requested media content that are encoded for a first bit rate to the client system; determining, by the server, that delivery of the portions of the requested media content that are encoded for the first bit rate can be changed to delivery of portions of the requested media content that are encoded for a second, different, bit rate; upon the determination that delivery of the portions of the requested media content that are encoded for the first bit rate can be changed to delivery of portions of the requested media content that are encoded for a second bit rate, stopping delivery of the portions of the requested media content that are encoded for the first bit rate to the client system; and delivering portions of the requested media content that are encoded for the second bit rate to the client system, from a point in the requested media content where delivery of the portions of the requested media content that are encoded for the first bit rate was stopped; wherein the media content is logically or physically divided into chunks; and, the delivering the portions of the requested media content further comprises: stopping the delivery of the portions of the requested media content that are encoded for the first bit rate at the end of a media portion chunk of the requested media content that is encoded for the first bit rate; and delivering the portions of the requested media content that are encoded for the second bit rate from a beginning of a media portion chunk, of the requested media content that is encoded for the second bit rate, where the beginning of the media portion chunk in the requested media content that is encoded for the second bit rate is sequential in time with the end of the media portion chunk of the requested media content that is encoded for the first bit rate. receiving, at a server, a request for a media content from a client system of the plurality of client systems; delivering, by the server, portions of the requested media content that are encoded for a first bit rate to the client system; determining, by the server, that delivery of the portions of the requested media content that are encoded for the first bit rate can be changed to delivery of portions of the requested media content that are encoded for a second, different, bit rate; upon the determination that delivery of the portions of the requested media content that are encoded for the first bit rate can be changed to delivery of portions of the requested media content that are encoded for a second bit rate, stopping delivery of the portions of the requested media content that are encoded for the first bit rate to the client system; and delivering portions of the requested media content that are encoded for the second bit rate to the client system, from a point in the requested media content where delivery of the portions of the requested media content that are encoded for the first bit rate was stopped; wherein the media content is logically or physically divided into chunks; and, the delivering the portions of the requested media content further comprises: stopping the delivery of the portions of the requested media content that are encoded for the first bit rate at the end of a media portion chunk of the requested media content that is encoded for the first bit rate; and delivering the portions of the requested media content that are encoded for the second bit rate from a beginning of a media portion chunk, of the requested media content that is encoded for the second bit rate, where the beginning of the media portion chunk in the requested media content that is encoded for the second bit rate is sequential in time with the end of the media portion chunk of the requested media content that is encoded for the first bit rate. stopping the delivery of the portions of the requested media content that are encoded for the first bit rate at the end of a media portion chunk of the requested media content that is encoded for the first bit rate; and delivering the portions of the requested media content that are encoded for the second bit rate from a beginning of a media portion chunk, of the requested media content that is encoded for the second bit rate, where the beginning of the media portion chunk in the requested media content that is encoded for the second bit rate is sequential in time with the end of the media portion chunk of the requested media content that is encoded for the first bit rate.