Hello,
Just a "anecdote" to proof..the fatigue is a factor of senseless errors.
One day (quiet sea ..full visibility) a supply ship stuck at good speed in a pontoon of our drilling rig....
No human casualties..thank's god.
In the examination who follow....the supply ship captain testimony he was sure (in his head) he was manoeuvring the engines control lever as he approach the rig...but in fact..due to his enormous fatigue (no sleep from 28 hours due to the fear of the first deck officer incompetency)..his body no react at his brain orders...
So...I believe the fatigue factor is one of importance.
Regards.