Breeze mentioned something today about adjusting triple stab. Something like making it so the accuracy on the third stab was better, but that the proc for a mob taking extra damage for a couple of rounds would only trigger if all three stabs land.
Right now triple stab has about a 20-25% rate of going off, and for a thief prime (using this because that's what I am) the accuracy of the stab is about 20%. Yes, that's an 80% whiff rate on top of it only having a chance to land 20-25% of all backstab attempts.
If accuracy for the third stab was raised to be more in line with regular backstabs, or scaled up in a way that it's more accurate as your str/dex/hit raise I think it would be a better overall skill. Being able to see something improve over time as you can get higher max stats and eventually rebirth and buy the max stats for even further improvements would be a good change as far as I'm concerned. It would also address some of the "risk" of a thief, because right now with it being massively inaccurate it only provides failure instead of risk.
For what it's worth 1st and 2nd stab accuracy combined is usually around 85%.
And on the point of hitroll helping land stabs, right now we're estimating some sort of soft cap around 25 hitroll. As I've leveled up after rebirth I generally found that to be true. Before I was at 25 hit my accuracy was lower, but when I started getting 25+ it seemed to normalize with the status I would see when I was 9x40 with 36 hitroll. For what it's worth thief gear is overflowing with hitroll and with max gear and shop purchases my hitroll would be in the low 40s, which could also mean 15+ hitroll that is wasted.