Ask a Thief Thread.

Does Haste have a prereq? ;_;



So the string is wrong? lolnexon.

Double Stab has been 140% since v0.56 along with the other skill updates and the strings for all of them have been wrong since then.

One thing I want to note is some weapon speeds. Double Stab is the same at Fast (5) With Booster or Fast (4) with or without.
This is with the same level of Mastery.
Fast (5) No Booster 20 Savage Blow > 20 Double Stab
Fast (5) Booster 18 Savage Blow > 20 Double Stab
Fast (4) No Booster 21 Savage Blow > 20 Double Stab
Fast (4) Booster 15 Savage Blow > 20 Double Stab
Yes there is a very significant difference between No Booster and Booster for Fast (4). If you're asking how, Fast (4) Double Stab is significantly faster than Fast (5) while the boost to Savage Blow is not as such (9 more hpm with DS to 6 more with SB).

Easiest Fast (4) weapon is the Korean Fan I believe though, and all STR daggers until 50.

What it boils down to is whether to want to be stronger at the higher level or stronger at the lower level, but both are equal at 45 if you do it right.
So really, what it is is Can I train with Double Stab for 13 more levels or do I want to do it for 8? Do I really care if I out damage someone who uses Double Stab when I'm level 40~44, even though he was out damaging me from 32~39? If you CPQ this might be a bit more significant, though your XHKO rate and speed is more important.
To be even more specific, the general build is:

 Spoiler

L	Savage Blow	Double Stab
30	+1 Mastery [1]	+1 Mastery [1]
31	+3 Mastery [4]	+3 Mastery [4]
32	+1 Mastery [5] +2 Booster [2]	+3 Mastery [7]
33	+3 Booster [5]	+3 Mastery [10]
34	+3 Savage Blow [3]	+3 Mastery [13]
35	+3 Savage Blow [6]	+3 Mastery [16]
36	+3 Savage Blow [9]	+3 Mastery [19]
37	+3 Savage Blow [12]	+3 Booster [3]
38	+3 Savage Blow [15]	+3 Booster [6]
39	+3 Savage Blow [18]	+3 Savage Blow [3]
40	+3 Savage Blow [21]	+3 Savage Blow [6]
41	+3 Mastery [8]	+3 Savage Blow [9]
42	+3 Mastery [11]	+3 Savage Blow [12]
43	+3 Mastery [14]	+3 Savage Blow [15]
44	+3 Mastery [17]	+3 Savage Blow [18]
45	+2 Mastery [19] +1 Booster [6]	+3 Savage Blow [21]

Bold is the better DPS. Both builds start off at even ground.
It's pretty insignificant to begin with, but combined with the extremely stable damage of Savage Blow's multihits, your need for mastery isn't as significantly high as the other jobs are.
And as always, putting your points into Mastery instead of finishing off your 21 Savage Blow gives better damage.

There's a minor alternative where you can forsake your Booster and go straight for 21 Savage Blow, but it achieves the same result at 40 because 21 Savage Blow 1 Mastery won't out damage 19 Mastery 20 Double Stab without Booster. Comparatively, you can move Booster earlier if you have a Fast (5) Dagger and it will improve your damage with Double Stab too. Otherwise, it is wasted as Double Stab already hits its speed cap at Fast (4) unless they've changed that (which means there's significant information to look at in terms of these builds). If you want to check, you should be hitting 100 attacks per minute with Double Stab with any Dagger with Booster on or Fast (4) alone.

tl;dr it's all really the same pomegranate, and after 45 you should have 19 Mastery 6 Booster 21 Savage Blow and be happy with life until the Steal build comes around. Savage Blow is worthless without Booster compared to Double Stab. Do you want to Double Stab until 43 or 38? Do you want to be outdamaging other Bandits from 32~39 or 40~44?

P.S. I hate my life. I can't believe I wrote all this to have that stupid conclusion.