Std Dev, Standard Deviation.
It's a mathematical function in statistics and probability that refers to dispersion or variation from the average.
With only five data points each, it doesn't mean much, but if I get to say 100 data points, it might show something interesting, such as a particular skill having a high chance of being a lot slower or faster than the average time.
This is important with WoS because it shows the user error or other factors. E.g., the slimes taking up some of the spirits or spiders damage.
WoS didn't get much improvement from PtV and it may not be sustainable for battles much longer than 20s.
Part of my spreadsheet is whether it is sustainable. Under the 'Skill Use Description' tab I noted WoS + PtV + BR was not mana positive for my setup, at 59 mps. I tested this by standing in town and blasting until my character said OOM about 25~30s later. My mana per second was oscillating between about 108 and 112.5, iirc.
1. By the way, one combo you can test is a spammable + Resentful spirit. This combo has potential but it's hard because you need to cast it every 2s.. not too early or too late to get that 383% weapon.
Sorry I am confused, what specific skills and what is the pattern? Do you mean blazing spiders + haunt resentful spirit?
Also, I just tested, and with my setup SiW, PtV, BR, and RoE is not mana positive. However, if I used spirit walk honored guest, PtV, blood ritual, and RoE, it becomes nearly infinite, that is I was spamming it for at least 2 minutes. I don't imagine a scenario where I could stand still that long and not have to move. If I moved, I would certainly be mana positive.
edit: Fyi, I am updating the spreadsheet as time goes by. I added three or four more tests, including SiW and widow makers/bears.