0747 GMT March 30, 2020
Assaults on Betsi Cadwaladr staff fell from 559 in 2013-14 to 278 in 2017-18, BBC wrote.
It attributed the fall to a team of specialist nurses who train carers and frontline staff in ways to avoid confrontation and improve care.
Ward manager, Matt Jarvis, who was punched in the head by an ‘acutely psychotic’ patient, said restraining people created distrust of staff.
Instead, people on the wards will attempt to talk down agitated patients or even distract them.
They are trained in how to restrain people, which is used if other efforts have failed.
Jarvis, who works on a psychiatric intensive care ward, said, "We need to make sure we're trying to understand the patient first.
"When people are admitted to a mental health unit, they may be afraid, they may be scared."
Staff try to create a rapport with patients and earn their trust, as well as giving them space if needed, in a bid to avoid a situation where physical restraint is needed.
After a large fall in assaults in 2014-15, the figure dropped further from 331 in 2016-17 to 278 in 2017-18.
A health board spokesman said only "a small number of NHS providers in the UK" employ such a team on a full-time basis.
The four-strong team give staff violence and aggression prevention training which aims to equip them to recognize triggers in patients and be able to calm them down.
Similar assaults on staff rose by 25 percent across the UK in the four years to 2017, although England accounted for most of the rise.
Mental health nurse Gareth Owen, who leads team with colleague Lisa Powell, said, "The better we can understand and meet our patients' needs the better their outcomes will be.
"We're determined to build on the progress we've made in recent years because one assault on a member of our staff is one too many."