Stun Skill landing success

I want to use the stun skills of my gladiator for occasional stunning and don't want to waste SP for nothing so I was wondering:

What has influence on if a stun attack lands or not?

- Skill type: Stun Attack/Hammer Crush
- Level of Skill
- Grade/P.Atk of weapon
- Character Level
- STR attribute (as the opposite of CON for resistance)
- Character type

From my experience and knowledge so far I think the Grade of a weapon as well as the P.Atk of it has likely no influence on the probability of stun. I stunned as well with an NG hammer as with an Elysian Axe. However I found character level and STR attribute to play a role in this as I was significantly stunning better with a +4 STR tatoo on my gladiator advancing in levels than my dwarf. This is also my explanation for the last point instead of the popular "dwarf stun nerv" roaming on the boards. The lower Stun Attack skill also seems to land less often on higher level mobs compared to the Hammer Crush skill but also works occasionaly for me.
unnessecary

However I am unsure if skilling the skills will improve my ability to stun. I just know it increases the damage given with the stun attack but have no ability to compare it so I left the skill level at 1 currently.

If anybody has general experience or more insight in this I'd be happy if you could share it. I found not very much information about it and don't want to spend millions on SP unnessecarily which I surely need later.

skill lvl vs lvl of mob/player (usual)

u can use a 1 patk blunt and land stun, but damage will be alot less

not sure but i think if u use SS it has higer chance to land, correct me if im wrong ^^

skill lvl vs lvl of mob/player (usual)

u can use a 1 patk blunt and land stun, but damage will be alot less

not sure but i think if u use SS it has higer chance to land, correct me if im wrong ^^

yup skill lvl vs player lvl (although ive failed 9 out of 10 on lvl 40 mages)
you can use a chrono (damage will be less but not much due to power to pattack ratio)
ss MAY give it a higher land rate but i really couldnt say, my stun rate is lame with or without ss

Each stun skill has a base chance to land and this chance increases with every level of stun. The game takes away from this chance with a bunch of things:
CON of the target
level of the target
Resist shock reduces this chance
Majestic set bonus
passive knight skill @ lvl 76 reduces this chance, too
lionheart self buff

It doesn't get any simpler than that really for stun. There are no other factors to be had.