1- The knife must not have a sharp edge to avoid cutting when it is gripped by the blade.
Is not true; The knife must have a cutting edge, for two reasons; Because if it has no edge it is not a knife, it will be a metal piece with a point, but it will never be a knife, and because you can throw a knife with cutting edge without danger of being cut, as seen in the gyroscopic throwing knives.
2- It is necessary to measure the distance so that the turns that give the knife in the air are the correct ones, so that the tip arrives at the target and sticks
Not true: with gyroscopic knives you get any distance and go through the air always aiming at the target (there are 40 meter shots on video at flyingknife.com)
3- In order to vary the distance to which it is launched, it is necessary to take into account what the knife travels on each turn and to separate from the target only that distance.
It is not true: with gyroscopic knives one can place oneself at a distance from the target one wants without limit, they are flying straight through the air and always nails.
4 - Getting nailed consistently is a work of many months of practice
Not true: with the gyro dart knife you get to start nailing safely to 6 meters away after 10 minutes of practice
5- "But first": For a fixed distance, the classic form needs a first test shot to adjust the distance and try to nail it with the second shot.
Not true: with gyroscopic knives, a test shot is not needed: they stick to the first one.
6- A real knife, with cutting blade, handle and crosshead is difficult and dangerous to throw it by the blade
It is not true. Gyroscopic knives need not be thrown by the blade to get them straight through the air like an arrow.
7- Rebound. All the throwing knives bounce against the target and you have to be very careful with the rebound, as they can hurt the thrower.
It is not true: The Gyroscopic knives have a Zytel handle that absorbs shock energy and minimizes bounces, so a defective shot is not dangerous.
8- All throwing knives rotate in the air around their center of gravity.
It is not true. The gyroscopic knives do not rotate around their center of gravity, they go through the air spinning like the barrel of a revolver.
As you see gyroscopic knives constitute a real revolution in the field of throwing knives. You can see them at flyingknife.com