Duel wield/double attack percentages/code? (warning: mathy)

[koros]

Anyone aware of how duel wield/double attack percentages work by class/level/skill? Or maybe the server staff is willing to share the code like they have for damage bonus.

Basically I'm trying to mathematically determine the ratio/level threshholds for when and if I should switch to duel wield (Jade mace + wurmslayer) as a ranger instead of using a 2 hander (woodsman's staff).

You can ignore my math jargon but, the "sweet spot" that should be more or less normally distributed around for a jade mace primary is 26-29 from 50-60 following the formula ( base damage x 2 + damage bonus), which divided by delay gives it a "rating" of 1.44-1.61 from 50-60. The wurmslayer offhand has a "sweet spot" of 50 (weapon damage * 2), and divided by the delay of 40 has a "rating" of 1.25, which is then multiplied by the % that duel wield fires to determine its real rating.

Woodsman's staff as a 2 hander of delay > 27 and < 40 has a damage bonus of 14-17 from 51-60 according to code Rogean has previously mentioned. This gives it a "sweet spot" of 76-79 and a "rating" of 2.17-2.25.

So long story short, for duel wield to be better, the offhand needs to have an effective rating of .64-.73 (from 60-51 respectively). Anyone know how often duel wield fires, or the formula to determine it?