To extend or FredT's excellent summary:
In any physical endeavor, people keep thinking that the way to win is by being big, tough, strong, knowing a 'secret', or having 'gear' or a weapon.
The real answer is:
1. Training method. You must have an effective training method to use your skill or tool, be it a physical tool or a skill (tool). Your training must be "alive" (resistance, timing, footwork and unrehearsed (force-on-force, plus).
2. Your ability to 'fight' with the 'weapon' (or skill). People with a gun who do not know how to fight with that gun will not be (as) effective.
3. Your mental approach - can you do it, can you react
4. Moral highground - If you are a somewhat moral person and you enter into a 'fight'/confrontation and you are not sure if you have the moral highground, you will not be able to fully react and fully engage.
5. Functionalizing your skill. You may know 20 ways to throw, shoot or armbar an opponent but unless you can bring that to bear during a fully resisting opponent, you will not have functionalized your skill. You will not 'remember it' under the stress of combat. You can teach a person who is not a fighter how to jab, cross and uppercut on the bag, but put him/her in the ring and they slap wildly at the opponent when being hit at the same time.
...and so forth. Attributes only mean so much. A big strong Arnold, with training, STILL could not swing a sword effectively in the first Conan movie.
$.02
