Wouldn't 100% bonus onto the base of 16-18 be a new base of 32-36?
Not quite, taking into account other modifiers it works more like this. (my example was an axe with JUST lumberjacking)
Max bonus from stats + anat + tact is 166.25%, add in 100 for max from items, 266.25% damage bonus. Add 100% from buffs (anything above 100% from buffs would make LJ damage useless, as LJ + buffs + items is capped at 300%) 366.25%
Lets use an ornate for example. 18-20 damage at the massively high speed of 3.5s
I'm only going to count max damage here for simplification.
20 * 4.6625 = 93.25
now for the LJ bonus, which adds 100% on 5% of hits
20 * 5.6625 = 113.25
That's a 20 point damage bonus on 5% of hits to someone butt naked (average of 1 point per hit damage bonus)
In a 70 suit those damages are...
27.97
and
33.97
A 6 point difference with an ornate at max damage (that's an average of 0.3 damage per hit, on the hardest hitting axe available)
Assuming max damage to an armored foe, and assuming flat 5% hits, and 50% SSI on the orante (giving it 1.5s swing speed). You will crit twice per minute, so this is a 12 damage per MINUTE bonus.
Not a great way to spend 100 points IMHO :/ (unless you only fight naked people!) It MIGHT be usefull if there was a high damage axe weapon with AI, but only the hatchet has AI so even if using AI every hit with a hatchet the bonus is only 15 damage at 5% of hits, or 0.75 damage per hit average (hitting with armor ignore)
EDIT: Short version, due to the way it's calculated, whatever the base damage of the axe is is the exact number of the additional points of damage it will do on LJ critical, after all damage calculations but before armor. Also changed my post to show damages instead of bonus so it's less confusingly worded.