[jacquesm]

I've codified this method (and a couple of others) in pianojacq.com, the 'slide/easy slide/normal and slide/perfect' methods are specifically meant to automate the process of breaking up a piece in overlapping segments. At the end of a run (the end of the piece) it extends the segment length by doubling it and then loops back to the beginning until you can play the piece. It really works and the speed with which you progress through a piece is a huge improvement compared to some other ways in which you could approach the problem, but it is not without downsides, it tends to demotivate people that 'just want to play', which is fine (there are options for those people as well). Practice is fundamentally different from performance, and it would be good for all aspiring pianists to have this tattooed onto their foreheads in mirror image so that you are reminded each morning.