This thread has rightly matured to include the debilitating effect of fatigue on human performance.
There also seems to be an acceptance that fatigue is a bigger problem than alcohol.
That may be so, but as far as the effect on performance is concerned they are surely equal?
I do not know of any research that demonstrates whether one is better than the other, but we need to be aware that either or both together are likely to result in at least an incident/accident/fatality.
There seems to be an acceptance that alcohol consumption is a question of degree, i.e. how much is still affecting the individual at a moment in time; that is of course true, but as far as driving is concerned in the UK there is a lively debate on how much one can drink to establish whether a breathalyzer conviction is likely or not. My submission is that in aviation terms the answer has to be assumed to be zero, and we should move towards that as the acceptable limit.