Tested out Quick Claw. I gave two Smeargle Quick Claw and had them spam Spore against a Meditite in a Double Battle.
Quick Claw activated 12/50
Seems like it activates around 25%.
you know that a sample with 50 tries in pkmn is irrelevant...
well, this took me around 2 hours, which is kinda fast...
QUICK CLAW
quick claw lv.100 marowak with false swipe VS wild lv. 16 bidoof
I battled 3 bidoofs, at lv. 16 it has 135 PP and one of its moves is rollout which can last up to 5 turns, so don´t be surprised that I was able to get 192 false swipes against one bidoof
the first and second bidoof were attacked 192 times, the third 128 times (so I had a pretty nice pkmn number 512)
15/64 (1)
15/64 (1)
12/64 (1)
18/64 (2)
6/64 (2)
13/64 (2)
13/64 (3)
13/64 (3)
total: 105/512 = 20.5078125%
well, it was interesting to see that I had exactly 60 activations in the first 256 tries, which meant 23.4375% which you may recognize, but I went on and, well, you see the result, 45/256 after that
to compare:
18.75% (48/256) would be 96/512
20% would be 102-103/512
23.4375% (60/256) would be 120/512
so my result is still nearer 18.75% than 23.4375%, this can probably be solved only by looking at the game code
if anyone else who wants to test this, I recommend a high lv. marowak with a PPmaxed false swipe (64PP) against a lv. 16 bidoof west of hearthome...