haven't had anything to drink since saturday. but yeah one of my recent really good jumping days was after drinking a fair amount the night before. a month ago or so.
there does not appear to be much rhyme or reason to when i get hung over, with the caveat that obviously i have to have SOMETHING to drink. but there are nights when i have four drinks and am wrecked the next day, and nights when i have seven drinks (very rare now) and am totally fine.
I'm impressed that you can limit yourself to four drinks. As soon as I start drinking I end up drinking til I'm out cold. If I start drinking early in the day I'll usually end up having a dozen+ beers. Lately I've been drinking later and instead of buying a carton just buying a 6 pack. By the time I've finished the 6 pack I still want to drink more, but by that stage the bottle shops are closed.
Drinking does have negative effects, but I've read a lot of biographies of athletes from various sports and many (especially in Australia) will never give up drinking. Nathan Buckley (one of the best Australian Football players in modern times) said quitting drinking actually affected his performance negatively. The one season he gave up for 6 months it was his worst season ever, and as soon as he resumed drinking on the weekends his performances improved. Same as Peter Norman the fastest ever Australian over 200m. He became an alcoholic after retirement, but in his biography he mentioned getting pissed regularly in the weeks before his 20.06 200m at the 1968 Mexico Olympics. Him and John Carlos got pissed together 2 days before their meet a couple of years later in the US and Peter Norman ran a 100m PR in that race.
Obviously drinking is not beneficial, but I agree with Eric and Coges in the fact that none of us are professional athletes so there's nothing wrong with the weekly/occasional drinking session to unwind.