[quote="D. S. Smith"]I can see a moderate amount of alcohol as being both beneficial and detrimental to a medieval soldier. It can make you less susceptible to blunt trauma since your body is more languid, as in the classic example of why DUI drivers are often less injured in a crash than the sober motorists they run into.

On the other hand, it is a proven fact that even a very small amount of alcohol (1 beer) significantly increases your perception and reaction time, which I could see as being very detrimental on the battlefield.[/quote
That is a load of bullshit. The first you are ignoring the fact that one of the reasons that alcohol for the most part is a depressant and the amount needed to be considered driving under the influence is more than drinking one beer and that drinking one beer as different effects on the body drinking several and also ab drinker that DUI under the influence are more reckless, more likely to speed, etc weight x speed equals more energy thus something going faster hit something going slower, assuming the car are similar, the faster the car the more energy it is putting into the lower car, the more force the slower car is receiving and thus the less force the faster is receiving less damage than the slower car and driver. Also you used the phrase moderate drinking for the first one very light for the second, giving the idea the alcohol is stimulant, which has been proven not to be the case.

I think there was a misunderstanding there regarding "increasing ... reaction time." It is easy to confuse that to mean "increase = improve" but it actually means the reaction time is longer (i.e. slower), as in short reaction time is better and long reaction time is worse.