eg. white walks over to a8 and promotes to a bishop
why do I lose when the clock runs out?

6.9 |
Except where one of Articles 5.1.a, 5.1.b, 5.2.a, 5.2.b, 5.2.c applies, if a player does not complete the prescribed number of moves in the allotted time, the game is lost by that player. However, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves. |

I'm not complaining, because I really didn't deserve the win, but why did this get called to a draw? https://www.chess.com/live/game/2640814079
Chess.com uses a hybrid of USCF rules in determining these cases. Under USCF rules (unlike FIDE) a helpmate cannot be considered.
On this site that means a simple piece count of the player with time remaining is used to determine the result. K+B cannot force a mate, so result is a draw.

So in a 1 minute game, like the one I just played my son and apparently lost coz my clock ran out, i might have faired better if i had ignored what was going on the board and just concentrated on making the fastest moves possible regardless of strategy.. sounds more like chno than chess!

Smoothfang
Im complaining, because I really didn't deserve the win, but why did this get called to a draw? https://www.chess.com/live/game/2640814079
From my understanding, there isn't sufficient pieces at your disposal to create a check mate. the pawns aren't taken into consideration here, only your bigger pieces. hence, as you do not have enough pieces to check mate, this game is seen as a Draw because even if you had sufficient time, you couldn't mate with just a king and bishop.
but I can mate white there