Skirmish II Coffer Rank Up

[Danita]

Can anyone figure out how to make the coffers rank up, because we got rank 4 coffers on 5/5/x twice, made great money (and gear), and then on our next four runs we got no rank ups on the coffers and lost millions.

If this mechanic can't be figured out, then I'm probably done doing anything besides 1/1/1 for Bayld, as 5/5/x runs are far too expensive to lose money attempting fruitlessly.

Thanks!

[MarkovChain]

I have done many V/V/V runs, like 30 or something. The rank up rate is about 50%. When you don't rank up you are getting many verdigris stones +1, which sell quickly for 180k at the AH and partly reimburse the run. When you rank up, you get often get ~8 verdigris stones +2 between the 6 persons and many +1s too. To my knowledge it's the only way to reliably get +2 stones. The cost of V/V/V is roughly 3M to split between 6 so it's not that much and on average it's worth your money. Low tiered runs are definitely a waste of time though.

So far my conclusions are :

Head V = more chance at rank up, stones +1 are common.
Rank up = more chance at +2 stones.

(this was probably the case in skirmish v1 but it was basically impossible to get tier V head at the time..)