Talentless, is that knife above a Sykes-Fairbairn knock-off?
I personally, don't believe a knife is much of a defensive weapon.
Hell of an offensive weapon though, if you have the stomach to use it. However:
You have to get into arm's reach to use it.
Most places frown on carrying a blade that's more than 4 inches long.
And did I mention that you have to get in arm's reach to use it?
By the same token, if you are accosted by a man with a knife, he should be shot (double-tapped) if he is inside of 20 feet.
If you do the math, a motivated person can cover 100
yards in about 10-12 seconds.
So, 10 yards can be covered in
1-second.
20 feet (about 7 yards can be covered in about half that).
Some will laugh, but I'm beginning to believe that one of the better weapons for self defense is a 3-inch .38 spl. Loaded with 200-grain Semi-wadcutters.
It's controllable, even your girlfriend can get off an accurate second shot.
And while that bullet ain't moving really fast (800 fps or so) it's gonna start tumbling when it hits it's target, tearing a devastating wound channel.
Also, the bullet will stay inside the assailant, and not exit and harm someone down the street.
Yea, you might have to double tap him, but you were gonna do that anyway. (Being as a "one-shot stop" is virtually gauranteed if you hit him twice.)