Ask a Thief Thread.

I decided on a new build after Level 21 Savage Blow:
Level 38 = +2 Mastery (3), +1 Savage (22)
Level 39 = +2 Mastery (5), +1 Savage (23)

So at Level 46/47 youlll have SB and Mastery maxed while your damage improving always.

That was the build I advised my bandit friend. 1 into mastery, 21 SB, then 2 mastery/1 SB per level. That or 6 boosters after 21 SB and then 2 mastery 1 SB. Just make sure your mastery stays odd until you finish maxing out all your important skills. This build cost more pot money, which she has plenty.