Hi,
Losing positions can be simple or complex, often it can be relative to the skill of the players playing and subject to specific positions. For example, there can be simply lost positions with a one pawn advantage, such as many endgame positions that arise, and complex but lost positions with an extra piece advantage, often during middle games. It is all relative to the positions, pieces on the board still, and skill of the players playing. An example, see this game where my opponent struggled to consolidate his early winning advantage, and eventually lost. Hardest games to actually win are those where you have obtained an advantage and must see it through!
-Jordan
Are losing positions always simple or can they also be complex in nature?