How many alcoholic drinks does it take you to black out?

I was wondering how many alcoholic drinks does it take you personally to black out (i.e. how good are you at drinking). I usually black out after about 14 to 17 drinks, but occasionally I will remember everything for 20+ drinks. I know everyone has a different tolerance for booze, I was just curious how the booze tolerance correlates to your susceptibility to blacking out. I can usually drink about 25 drinks in a night, but most of the time I don't remember the last 10 or so drinks.