Abstract: A playback apparatus for use in a reproducing system is disclosed. The playback apparatus includes a number of conventional elements including a memory configured to store data to be read from a data source (1), a presentation unit (340) configured to retrieve one or more data blocks from the memory for presentation to a user and a controller (365) configured to manage the contents of the memory and control the operations of said data source (1). In addition to the conventional elements, the controller further comprises an access prediction unit (370) comprised of a ranking unit (360) and a candidate identifier unit (355). The candidate identifier unit (355) is configured to select a set of candidate blocks (at least two data blocks) from a plurality of data blocks stored on the data source for consideration by the ranking unit (360). The ranking unit (360) is operable to rank the desirability of a set of candidate blocks from among the plurality of data blocks stored on the data source.