Mulligan smoothing does not properly account for 'X' CMC cards
I'm aware that Arena has a 'smoothing' algorithm designed to reduce the chance of mulligans by giving players a better chance to have a starting hand containing the nearest number of lands to their CMC, but I've noticed that this doesn't properly account for 'X' CMC cards.
I've been playing a simic ramp deck at my local game store for quite some time now and had been having no problems with starting hands (I'd mulligan in around half of the games I played, rarely more than once, but that seemed fairly normal), but when I replicated the deck on arena I found myself struggling to get a good starting hand, frequently mulliganing to five and just having to make do with whatever I had.
I quickly realised something was wrong, so I looked into it and found an article about Arena's 'smoothing' algorithm, realising that to be the problem.
I run 28 lands in the deck, so I should see 3-4 lands on average in my starting hands, but I was only ever seeing 2-3 lands, which made sense with the smoothing algorithm, as Arena recognised the average CMC of the deck as being roughly 3. The problem is that I run 'X' CMC cards such as Hydroid Krasis and Finale of Devastation, which Arena recognises as having a CMC of 2, even though I would never cast them for that. Typically I would never cast them for less than six or seven mana, so if Arena took this into consideration this would raise the average CMC of my deck to around 4, which would cause the smoothing algorithm to give me far more 3 and 4 land hands, which would be a lot fairer.
Over recent months I have been attempting to get around this problem by altering my deck to raise the CMC that Arena recognises, and while I have had some success, this never lasts long as another update or a banning keeps putting me back to square one.
I've now run out of alterations I can make to the deck without completely rebuilding it, which I'd rather not do until rotation, as the deck still works fine on paper, so I'd really appreciate it if you could get this fixed so that I can see the deck off properly, as it is unlikely that I'll get to use it at my local game store again before rotation.