if you are going to use the WW points for booze then it is best to get the calories from the bottle if available. A normal pint of beer is usually 200kcal, a guinness is around 180kcal and a stronger beer is 220kcal. There will be no fat in most alcohol (expect weird liquers or cocktails with cream). Your calories and hence points come from 3 main sources, the alcohol, the sugar, the proteins. The alcohol is the big one, a 80% unsweetened vodka will have twice the calories as a 40% one. BUT a 8% beer could have less than twice the caloires as a lite beer of 4%. The proteins and other stuff are pretty minimal.
Alcohol is made by fermenting sugars, if you ferment them all out then it is left with no sugar so is not sweet, it is dry. Pilsner beers are usually brewed to completion and strong in alcohol and low in sugar. Lite beers are also brewed to completion but quite low in alcohol. So if you goal is to drink 6 beers no matter what, stick with lites, if you goal is to get to a certain tipsiness, then you might be better with the strong pilsner beers, they often have less calories per
% alcohol. Also being stronger they hit you more so you get drunk faster, even though you could have drank the same units of alcohol.
Also diet mixers have sweetners and studies show these increase absorption rate. So the most low cal/point method to fail a breathalyzer test would be to drink vodka & diet coke on an empty stomach really quick.
The rounding of WW points causes confusion, as Seaner showed.
Using this calculator for pints http://www.sublogic.com/points/uk/
Guinness, say 180kcal is 2.57 rounded to 3
Heineken, say 200kcal is 2.86 rounded to 3
A strong german beer, say 240kcal is 3.43 rounded to 3
Rounding to halves solves some of this obvious problem. But you should really go to 1 or 2 decimals, especially if you are going to be drinking loads. If you KNOW guinness is 180kcal and you are going to drink 8 pints, then multiply it up and put it in the calculator.
Coors light is 4.2% miller draught is 4.7%, there would only be a slight bit more calories/points in the miller, but by rounding 1 and 1.5 you have essentially said there is 50% more points in the miller, which is not true.
For a variety of everyday foods/drinks these rounded points will hopefully balance themselves out, it is when you go drinking 10 bottles or eating 10 portions of an item that it adds up.
If I went for a 2500kcal (~36 points) per day diet but stuff I ate happened to be estimated or rounded in such a way that I ate on average 5% too much, then I can expect to put on about 1 stone (14lb) of fat per year.
I would reckon I drink 50+ points worth of booze per week, so if I went by seaners 1.5 vs 1 point estimates in choosing my beer I could easily get that 5% difference.
Alcohol calories are overestimated for human consumption anyway, but thats a whole other thread!