The actual rule is if the player with time left has mating material, to include B+N or greater, or stupidly, even RP and K vs. K on the Queening square, that player wins, otherwise a draw. For example, if your time falls and your opponent has a lone Bishop, the game should be a draw. Two Knights would be a draw, as I understand it.
To put it in perspective, your opponent could have a Pawn on the 2nd rank with your King blockading it on the third, and you could have four Queens and lose on time. Yeah, I know it's silly, but that's FIDE and USCF rules. Conversely, your opponent could promote all his Pawns to a dark-squared Bishops and draw with 9 of them because there is no possible mate.
It's not point-based, it conforms to the international chess federation standard rules. As far as what you can do, you have this knowledge now, and that's the best I can advise you.
In a recent live game, my opponent went with perpetual checks to wind down the clock, knowing I would be ahead. Now, I have played a few live chess games, and, this has never happened in any of my games previously. It appears that if your time runs out, even if your opponent has 1 second left on the clock, but no pieces, he/she wins.
So, what is the sense of assigning a point value to the pieces? I lost on time, but, I was up about 9 points. This was a 15 minute game, and my opponent was at 24 seconds when I ran out of time-and lost. The 9 point differential is because I had a Q and he had pawns-he had no chance of winning if it weren't for the clock. It was a sure win for me.
I love chess. But, in instances like this, I'm dismayed that one can "game" the system to their advantage.
Instead of replying that I should have moved more quickly, or, not put myself in a position to be checked perpetually, I would like an explanation on the point value of the pieces, and how it is relevant compared to time.