Daniel Dorn said:Any knife which allows the blade to contact the backspacer/backspring and dull the edge, even if it's caused by putting pressure on the blade when closed. Most lockbacks are awful at this.
It's impossible to prevent forced blade dulling if you squeeze it on purpose (or sit on it wrong I guess) if a lockback has the release at the back end of the handle. A lot of Spyderco models won't do it because the little stop bump contacts the lock bar on the far side of the rocker pin, which is easily done because the release area is in the middle of the handle, so the rocker pin is a lot closer to the tang. It usually means the blade can't be squeezed, or at least requires a lot more pressure to do so.