The below test was completed in roughly 20 hours against a level 72 Ul'hpemde. I set up as Sam/Blm, no Brutal, no accuracy/dex gear and -acc rings, in order to minimize hit rate and ensure no other source of double attack. The results are from the Extra Attacks plugin of KParser (including an extra bit of collated info that I wrote up and will be included in the next release). I removed the DA/TA/Kicks sections as they aren't relevant to this test.
Basic Data Player # Melee Attacks # Melee Rounds Attacks/Round # Extra Attacks Motenten 31100 25410 1 5690 Player # +1 Rounds # +2 Rounds # +3 Rounds # +4 Rounds # >+4 Rounds Motenten 5685 1 1 0 0 Player # MultiAttack Rounds MultiAttack % Kills w/Min Attacks Kills w/<Min Attacks Motenten 5687 22.38 % 0 0 Treat As: Multi-attacks per attack (Zanshin): Player # Missed First Attacks # DA w/Missed First Possible Zanshin % Motenten 12636 5680 44.95 % Player Acc. Rate of First Attacks Acc. Rate of Second Attacks Motenten 50.27 % 66.67 %
25,410 melee rounds. 12,636 of those missed the first attack, so 12,774 hit, giving a 50.27% hit rate on the first round with a 0.61% confidence interval. Predicted hit rate based on acc vs evasion should be 50.0%.
There were 5680 rounds that had a DA after the first attack in the round missed (12,636) -- that is, Zanshin procs. Zanshin rate is thus 44.95% with a 0.87% confidence interval.
Of the 5680 Zanshin procs, 3787 connected (not shown, but extrapolated from the acc rate on second attacks). This gives a 66.67% hit rate with a 1.23% confidence interval.
Accuracy bonus from Zanshin is thus between 15.44% and 17.90% hit rate, or between 31 and 35 acc. 35 seems the most probable 'round' number in that range.
You'll note that there are reported to be 5690 extra attacks, whereas there were only 5680 Zanshin proc rounds. In the second row you'll see that there was one +2 round and one +3 round (ie: rounds with 3 and 4 attacks). This is obviously a parser error. The Zanshin numbers are restricted to only rounds with 2 attacks, so those mistaken multi-attack rounds won't affect the Zanshin outcome.
There are also five +1 rounds (two attacks) where the first attack was not missed. Again, parser error. The second attacks of those rounds will also have no impact on the Zanshin results because the first hit of those rounds wasn't missed.
Summary: Zanshin proc rate at level 75 is 45%, and provides a +35 acc bonus to the Zanshin hit (subject to correction based on additional sampling).
I also plotted out the effect of the extra attacks and accuracy bonus in Excel across all base hit rates. Excluding the impact of Double Attack traits and gear, Zanshin is effectively the same as a War's Double Attack trait (+10%) when base hit rate is 81%. It's the same as a +20% DA rate when base hit rate is 65%. At 90% base hit rate, Zanshin is the equivalent of +4.75% DA, and at capped accuracy it's +2.25% DA.
It is better to treat the effect of Zanshin as if it were +DA rather than +Acc, in terms of impact on damage. Zanshin does not allow your hit rate to go above the 95% hard cap, for example, although it does raise your average hit rate in any instance when you are not capped. Instead, it gives you more chances to swing, and a better chance to hit on those swings.
Extra trivia: The maximum number of extra hits (not just swings) due to Zanshin occurs at 41% base hit rate, where it reaches 155.3 out of 1000 rounds. The percentage of extra damage due to extra Zanshin hits, though, declines all the way from 20% hit rate (where Zanshin increases melee damage/TP by 67.5%) up to capped accuracy (where Zanshin gives the above mentioned +2.25%).
Edit: Bah, messed up some of the numbers. Fixing.
Edited, Nov 7th 2009 7:58pm by Kinematics
Edited, Nov 7th 2009 8:05pm by Kinematics