achieve: Just a few more note on this endgame:
The position after < 86... Kg8 > is the "textbook" position from which a mate in 17-19 is forced. 1) Play a waiting Bishop-move on the B1-A7 diagonal
2) After the Kf8, follow up with B to h7 - in order to force the king to < e8 > 3) Ne5 - leaving lone king 2 options
A) Back to f8, where the Nd7+ will allow a swift forced procession where the lone king will have to move towards the mating square < a8 > B) To < d8>, after which the B to e4, just behind the Knight, is mandatory --
After that a series of subtle maneuvres, which needs to be practiced, will lead to a nice mate, with the Knight and Bishop taking care of a lock-up of a6-d6 
click for larger view (Black pawns are the <no-go> squares for the King) The reason why this works so nicely is the fact that the Black King is not <fast enough> to A) <oppose> the White King, because of the Bishop forcing the king back a file, after which the White King can get closer in via the < d8 > that is vacated... B) To move over to the other side because of the Bishop being fast enough to keep it closed down AND be used to gain another file for the White King to move closer (E-file & d-file the c-file with the help of the Knight) Then, the final act --- take away <b7> with the right tempo (Bl. King on back rank) with < Nd6 > - after which the King has only a7 & a8 - and the mate in 2 follows. Playing around with this is very helpful in general and trying it all out yourself is the best way... NO Tablebases!@!! Like Fischer, just play for both sides as best you can!! A list of benefits from training this is listed in my forum profile. | 
