In the diagramed position below I have reproduced from memory a position in a game that I watched between an 11 year old boy who had a 1700 rating and a twenty-something year old life master. The master had Black. These two players had faced each other before. White spent about ten minutes looking at this and missed what I found in about 30 seconds! White lost this game. When I realized that White did not know how to play this kind of endgame and messed it up I told his coach to teach this kid how to play these kind of endgames. I cannot state that this coach actually did what I suggested. Again, two years experience playing chess lost to about 12. There is no substitute for experience.
The key idea here is to play the White King to d3 so as to keep the Black King out of White’s pawn structure. After that, White needs to avoid exchanging pawns and to move his Bishop back and forth between c1 and d2. It should be an easy draw. Instead, White moved his King do f2 which let the Black King into his pawns and lost.
Mike Serovey, MA, MISM
Author of Better Thinking for Better Chess