How to win winning positions

Very often I somehow manage to lose the game in positions I'm totally winning. I think I kinda lose the interest in the game when I see that the opponent is lost, but he keeps playing just to see if you lose on time or blunder and, with me, it happens all the time. How could I learn to easily convert winning positions? Is there videos or books about that?

My last 3 defeats:

There is no clear recipe or easy fix, converting winning positions is one of the hardest things in chess, even elite players throw away completely winning positions on occasion. First it's important to stay focused and attentive to the difficulties of the position. You're not clearly winning unless you can figure out a straightforward way to end the game. So you have to identify what's your advantage and play to use those assets to lead you to the end of the game. So no aimless move thinking it's winning anyway, which was the case in game 1 : even after giving back the piece White was still winning, but only by using the e file and an attack on the weakened king, limp play undid that in just a few moves. In the second game White grabbed all the material while development was not over which was not the right choice. The correct way of converting was to play Bd2 0-0-0 then open the center files to use the lead in development and black's weak king, which was also a safer way to play. So the second point is no crazy decision and risk taking when it's not justified : if your position is really good and harmonious you won't need that. Third point is watch for opportunities : like the Bxh3 tactic missed in game 3. Very often games are ended because the defending side overlooked something else while trying to patch up the main defects of the position.

You can't post in the forums yet. Play some games!