3 principles (Fine)
1. Without pawns, you must be at least a Rook ahead in order to force mate (exceptions: R+R wins against two minor pieces; four minor pieces win against a Queen)
2. If you are two or more Pawns ahead the win should be routine by advancing the Pawns
3. With only one Pawn advantage, you will win if you can use it to gain more material - it is not usually enough just to advance the Pawn. Often one Pawn advantage is thought to be a theoretical draw, although the practical difficulties may be very great. Winning by the advance of the Pawn may be won because it allows entry with the King, or causes distraction from one vulnerable side, or allows simplification into a known won ending.