Checkmate Etiquette ??
Yes, but by letting your clock run out you waste your opponent's time. Some people use this as an immature way at getting back at someone for beating them. It is polite to simply resign and let your opponent get on with the next game.
I let people play it out normally... when people resign when I have smothered mate or something I get disappointed...
I'll def resign if you're just trying to eliminate all of my pieces in end game instead of putting me out of my misery, but I'll let you have your checkmate if I feel like it's been a good game
Back in the day, when I played chess on Yahoo.
Time control: 40 minutes.
Either I or my opponent would do this. If one of us is down on time, time is also a factor. You have to checkmate in time. If my time or my opponent's time is down to 1 minute or less, time is another element of the game.
It is fair play.
Like life, time is also an element of the game.