Harder when tired

Why is it so much harder to play when you're tired? I've had a really stressful couple of weeks, and find when I come to play a few 10-minute games, I'm making mistakes I would never normally make...

It's harder to do things when you are tired , simple as that.

Very annoying. You know all the tricks and all the moves, but you just make daft mistakes. It's not like you're doing anything manually exerting. Very strange how the mind works.

As Fischer said, "Your body has to be in top condition. Your chess deteriorates as your body does. You can't separate body from mind."

I recently joined a chess club. It meets on Tuesday evenings. If I've had a really tough day, I'm almost scared to go! It's quite surprising how you just can't see the things you do when you're fully alert. It's not like you've forgotten everything. It's still there, but you just can't access it!

Either nerves or you don't sleep well enough maybe .

I've realised what it is. It's more difficult to maintain concentration when you tired. I can start games fine, and play my normal opening moves. But as the game develops, you find you lose concentration. This is why you miss obvious combinations or clear threats.