WanderingWinder wrote: Whilst I believe that the OP has been answered quite well, it is instructive to note that much better questions arise in Q+K v. R+K or B+N+K v. K. these are both technically won in positions when material isn't immediately lost, but can be difficult to pull off. I haven't seen anything wrtiten on how to do it, though I am sure there is something out there, but I eventually figured it out by myself. Still, I'm not sure I remember too well at this point...
Against tablebase defence ('flying rook defence') Q v R gets tricky. I have excellent notes on how to still do it; but i can't post them - they are someone else's copyright - search rec.games.chess.* archives c. 1992 - NM [USA] Roger Poehlman.
um ... helpmate in 5. different thing.
Even better are Selfmate prob: the matee forces the mater into a pos. where the only legal move by mater mates matee -iykwim :)