Relying on a structured observation guide listing a large number of variables shown to be good predictors of aggression in bars by past researchers, trained observers spent a total of 444 hours collecting data in 25 licensed drinking establishments in Hoboken, New Jersey. Observations took place at two separate time periods, 7:30pm-10:30pm and 11:00pm-2:00am, on Thursday, Friday, and Saturday nights. Logistic regression analyses revealed the absence of bouncers and doormen as the strongest predictor of aggression in Hoboken barrooms. This is a particularly important finding considering the frequency with which bouncers and doormen are vilified in the available research on barroom aggression. Several practical prevention strategies aimed at reducing aggression in bars are proposed. (Contains 3 tables.)