Draw Rules

Hello,

I am playing some 10 minutes games and it is the second time that happened that my opponent goes out of time and it is a draw.

In summary I was black with only the king and he was trying to checkmate me and he run out of time...

Why? Shouldn't I win as he runs out of time?

Thanks

Apologies if it is a stupid question but can somebody explain the rule here? 

You can never win if all you have is a bare king. The best outcome you can hope for is a draw.

https://support.chess.com/article/268-my-opponent-ran-out-of-time-why-was-it-a-draw

Essentially, if you can't possibly checkmate your opponent, you can't win. The site has slightly different rules, about possible checkmate with king+knight, king+bishop, and king+two knights, but those are explained in the above article.

oh ok... but does this make sense? I mean I guess it does but so basically somebody that cannot give mate has no risk to loose in this case? Isn't it an extra advantage?

I added some additional context as an edit. Time isn't the primary consideration; you still need to be able to mate.

ok thanks for the clarification Of course it make sense, like you said you cannot win, but I feel that with time control it does not make sense 100%, maybe only 99.99999

What's worse is a player can deliberately let his time run out and get a draw out of a forced mate position, since the site only considers the mating material on one side in declaring it a draw or not. For example, in this endgame, if white in a time scramble pushes the pawn:

And he realizes he is gonna get force checkmate, he can literally let his time flag at any point, and the site will declare it a draw cause it deems the knight and king insufficient mating material, despite the pawn blocking the king in.

If you want to call that an "extra advantage", OK, but the player has in some sense earned it by playing better than their opponent.

If your opponent only has a king left, you've earned at least a draw, since he could never checkmate you, regardless of time. The worst case scenario is a draw, that's why you get a draw if you run out of time.