
Using The Pre-move
Pre-move is where we move before it's our turn, and when it's our turn, it will move automatically like what we pre-move even if something unwanted happened. People (including me) use pre-move usually in fast time control game like blitz and bullet because pre-move only take 0.1 seconds of your time but risky you only can do pre-move if you are sure it will work well.
Look at the diagram above, it black to move, and should white pre-move Qxe5? The answer is no. Because black could also capture white's e5-pawn with the knight, not only the queen. so if white pre-move Qxe5 and black capture the knight white will lose queen for a knight.
Anyway, do you have your pre-move on chess.com? it could be useful for 1 min bullet lol :] here's the way to turn it on:
The first step is to go to settings
then go to live chess setting
In the live chess setting turn the [enable premove] switch on.
Save it then you will have your pre-move on.
So, in conclusion the pre-move is helpful for fast time control game but you need to be careful when using it.