I recently arrived at this ending and thought it might be worthwhile to examine it more closely. My endgame books, including Fine’s Basic Chess Endings, don’t even mention it. Not surprising, I guess, since it would seem that normally it should be a draw unless there are exceptional circumstances. But that’s always the case!
We arrived at the position below after Black’s 43rd move. I felt I had a small advantage and therefore some winning chances because my P was further advanced and my K has more room. The “plan” was to run the K to the vicinity of the K & P to seek shelter. Running the position through the Shredder Endgame Database revealed that the position is only a draw, but it seems, for the reasons mentioned, that the burden of holding the draw is on Black. On his 47th move, Black played the only move that loses! On my next move there is only one move that wins, but of course I didn’t find it. Fortunately Black did not find the only drawing move and after that the outcome was never in doubt.
Black made a brief comment after the game that he thought he lost because of his P moves. Evidently he thought he should have been checking with the Q. However, it turned out the real reason for his loss was when he played his 48th move and decided to defend the P and at the same time use his K to shepherd its advance. It seems counterintuitive to abandon the P by playing 48…Kb7, but that was the only move that would hold the draw. Apparently this is so because with 48…Kb7 he would be moving the K towards my P and thereby be able to hold up its advance.