EARLIER closing times, bans on selling shots and lockouts imposed on 14 Newcastle pubs have slashed the number of assaults by 31 per cent and could see similar restrictions extended across the state.

The first study into the effects of the restrictions imposed by the former Liquor Administration Board in March last year found at least 133 fewer assaults in an area that had the highest rates of assault in the state.

The director of the NSW Bureau of Crime Statistics and Research, Don Weatherburn, was ''stunned'' by results of the bureau's study which showed the restrictions were having a bigger effect on assault rates than any measure he'd seen.

''I've been watching successive governments trying to deal with the assault problem in NSW since 1988 and nothing has ever had any effect,'' he said.

''This is a substantial reduction and if it continues it will pull the state assault rate down and that will be the first time in over 20 years that's happened.''